Square Corner Blog RSS Feed

Hijacking Amazon EventBridge for launching Cross-Account attacks

Ramesh Ramani — Wed, 25 Jun 2025 07:00:00 GMT

AWS EventBridge is a serverless event bus service that enables powerful integrations across multiple AWS accounts. While this cross-account capability is essential for building modern, decoupled architectures, it also introduces potential security r…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Revamping Data Science Interviews

Daeus Jorento — Wed, 28 May 2025 16:00:00 GMT

Introduction

The goal of interviews is to assess a candidate’s skill sets, fit, and potential to achieve impact. Well-designed interviews can reduce both false positives (bad hires) and false negatives (rejecting good candidates). On the former, for a data scien…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Massively Multi-user Datastore, Synced with Mobile Clients

Tad Book — Thu, 12 Apr 2018 17:13:25 GMT

At Square, we manage large amounts of information for our merchants. This includes the data surrounding what a merchant sells — their products, prices, taxes, and the configurations associated with those entities. We refer to this dataset as a merch…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

An analysis of the Square and Cash App outage

Paul Friedman — Wed, 05 Mar 2025 11:00:00 GMT

What Happened

On February 26, we experienced a system-wide service disruption affecting Square payment processing and Cash App services. The technical root cause was related to a security certificate validation problem that temporarily prevented our payment syste…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

RoBERTa Model for Merchant Categorization at Square

Darshan Kabadi — Mon, 10 Mar 2025 05:00:00 GMT

Note: In this blog post, the words merchant and seller will be used interchangeably.

Introduction

Square’s vast ecosystem of products enables businesses to accept payments, receive banking services, utilize payroll, schedule appointments, and more. With its mission of economic empowerment, Square’s growth is grounded in enabling businesses to further scale their operations over time. In order to achieve this, Square’s overall product development, marketing strategies, compliance considerations, financial forecasting, and more rely h…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Mobile Payments SDK GA and New Terminal API Features

Priscilla Wu — Mon, 24 Feb 2025 07:00:00 GMT

When we opened our platform and provided developers with direct access to Square hardware, our goal was simple: to empower you to build custom, secure in-person payment solutions to meet the unique needs of sellers. Over the years, the Square Reader…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Best Practices for Using Third-Party APIs

W Ian Douglas — Wed, 05 Feb 2025 10:30:00 GMT

In the demanding landscape of financial technologies, optimizing API integrations is crucial for delivering high-performing and reliable applications. This article addresses key challenges faced by developers working with services like Square, or an…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Kube-Policies: Guardrails for Apps Running in Kubernetes

Hardik Darji — Tue, 28 Jan 2025 08:00:00 GMT

Introduction

In the fast-paced world of cloud computing, security shouldn't be a barrier, but a facilitator. Our Compute Security team's philosophy embraces creating guardrails instead of gates, guiding innovation securely without compromising speed. This blog s…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the Square Go SDK

Jordan Bergero — Wed, 18 Dec 2024 17:00:00 GMT

It’s Time to Get ‘Go’ing

After much anticipation, and many asks from our community, we are very excited to announce Square now has a Go SDK! For Go SDK details, please visit our website. If you are looking to get started quickly with the SDK, please check out this quick-start guide

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Enhanced Authorization with Square

Conrado Brenna — Mon, 16 Dec 2024 08:00:00 GMT

Square continually innovates to deliver industry-leading authorization rates and secure payment experiences. Through partnerships and cutting-edge protocols, we aim to make payment acceptance seamless, safe, and successful for every business. Below,…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Enhancing Data Quality Using Better Designed ETLs

Kasia Rachuta — Mon, 30 Sep 2024 16:00:00 GMT

Templates provide a helpful way to produce consistent results across data science teams. They can reduce cognitive load as your peers, stakeholders, and consumers will know what to expect each time. They can also guide you through best practices and…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Making Insights-Driven Decisions in an Ecosystem of Ecosystems

Stephanie Shi — Wed, 10 Jul 2024 06:00:00 GMT

In this blog post, we explore our data-driven methodology for measuring, securing, and monitoring Block’s distinctive environment. Our objective is to prioritize security and infrastructure initiatives using robust data and insights drawn from our e…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the Winners of the Square Local Community Hackathon

Eva Sasson — Mon, 24 Jun 2024 15:00:00 GMT

Square's Local Community Hackathon offered a platform for creative minds to reimagine the relationship between businesses and local communities using Square APIs. Participants brainstormed solutions that celebrated diversity, fostered community spir…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Recap: Square Unboxed 2024

Tristan Tyler — Mon, 24 Jun 2024 16:00:00 GMT

On June 5, we gathered in Oakland with over 120 partners and Squares for our annual Square Unboxed event. We had plenty of reasons to celebrate our work together. Here are the key takeaways:

Partnerships and International Lead Vijay Vachani shared the state of the Square platform, including which trends and investment areas Square is focused on in 2024, as well as the progress we’ve made on partner programs over the last year.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Q&A: Discover what’s new in the Mobile Payments SDK beta

Priscilla Wu — Thu, 06 Jun 2024 15:00:00 GMT

Six years ago, we launched the Square Reader SDK. Since then, we’ve had hundreds of developers and partners integrate the SDK into their apps and we’ve enabled thousands of sellers across diverse business types to seamlessly process in-person paymen…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Leveraging Linux Internals to Supercharge Osquery Malware Detection

Frank Graziano — Wed, 27 Mar 2024 16:00:00 GMT

Introduction

This post outlines what I believe to be a novel way to overcome the limitations of the osquery yara scanning table to find fileless malware on Linux operating systems.

Background

What is osquery?

osquery is a powerful open source toolset that exposes operating systems in a way that allows them to be queried with SQL. There are myriad use cases of this instrumentation, but we primarily use it to ask security relevant questions of our hosts. Over the…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Evolution of Developer Productivity at Square - Part Four

Korhan Bircan — Mon, 26 Feb 2024 17:00:00 GMT

Welcome to the fourth and final part of our blog series, where we focus on a crucial aspect of our journey at Square: Investing in Reliability and Test Engineering. At the end of the day, our goal is to deliver high quality products that delight Squ…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Evolution of Developer Productivity at Square - Part Three

Korhan Bircan — Wed, 14 Feb 2024 18:00:00 GMT

Welcome to the third part of our series on Square's evolving approach to developer productivity. In the first two parts, we delved into the growth of our codebase and the investments we made in CI infrastructure to increase development speed. Now, we'll shift our focus to platform-specific tools and methodologies that further boost development velocity. We'll also d…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Accept payments with Square using Next.js App Router

Anthony Giuliano — Thu, 25 Jan 2024 17:00:00 GMT

In this how-to guide, we’re going to walk through the steps of accepting payments in your Next.js app using the new App Router so you can build an end-to-end payment flow.

This tutorial requires a general understanding of the Next.js App Router. If you are not yet familiar with the major API changes of the Next.js App Router, you can check out [Next.js Learn](https://nextjs.org/learn).

All of the code for this payment flow how-to guide can be found in the Square Next Online Payments Example repo.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Evolution of Developer Productivity at Square - Part Two

Korhan Bircan — Mon, 29 Jan 2024 09:00:00 GMT

Kicking off the second part of our blog series, I'd like to talk about our efforts to address one of our most pressing challenges at Square: improving the development velocity. A recurring piece of feedback that came to light was a shared sentiment among engineers – the time taken to roll out f…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Peer Reviews for Data Science

Peter Weir — Wed, 17 Jan 2024 06:00:00 GMT

Peer reviews increase the quality of data science output by diversifying our thinking and decreasing the probability of making an error.

Once you’ve felt the terrible sinking feeling in your stomach, you never forget it. I was in my first year as a data scientist in my first industry job, still getting used to the tools and cadence of the tech world. My assignment was to analyze a fa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Evolution of Developer Productivity at Square - Part One

Korhan Bircan — Wed, 10 Jan 2024 07:00:00 GMT

Building on a decade of innovation and scaling, Square's growth story has been nothing short of remarkable. From the early days of a simple Square card reader connecting via an iPhone's headphone jack to an expansive ecosystem of business solutions …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How To Train Your Own GenAI Model

Alessandro Joabar — Mon, 11 Dec 2023 18:00:00 GMT

While GenAI is dominating the news and earnings reports across the world, a lot of emphasis is focused on massive, powerful, and expensive large language models (LLMs). Every business wants to slam their credit card on the table and integrate AI in …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Winners of the Square + Google Cloud AI Hackathon

Eva Sasson — Tue, 21 Nov 2023 07:00:00 GMT

Two months ago, Square and Google Cloud came together to foster AI innovation for sellers by supporting developers building with Google Cloud’s AI APIs and Square’s APIs. Over that period, almost 2,500 developers came together to build impactful sol…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

3 Ways to Drive Data Culture on your Team

Kasia Rachuta — Wed, 11 Oct 2023 06:00:00 GMT

One part of our jobs as data scientists is to drive data culture on our teams. This includes making sure that data is part of every decision, that we can quantify the impact we’ve made with new launches, and that we are making decisions analytically…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How Jetpack Compose Measuring Works

Helios Alonso — Thu, 28 Sep 2023 15:00:00 GMT

Jetpack Compose is a game changer for Android developers. It provides an easy and flexible toolset for building UI. However, using Jetpack Compose beyond its basic tenets Box, Column, Row — might need us to put a little more work into one of two related areas: mea…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Incident Summary: 2023-09-07

Square Engineering — Fri, 15 Sep 2023 23:00:00 GMT

Summary

Last week, Square experienced a multi-hour outage across our services. We understand that you rely on our systems to power your business and that’s a responsibility we take seriously. We apologize for letting you down and for the length of time it t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How To Measure the Value of Internal Tools

Chang Liu — Wed, 02 Aug 2023 16:00:00 GMT

What Are Internal Tools?

At Square, we use all kinds of internal tools to help improve our productivity and efficiency. In our org (Seller Experience), we use tools to effectively manage our data and provide engineering and analytical support to a variety of internal users.…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Supercharging Continuous Integration with Gradle

Paul Hundal — Thu, 27 Jul 2023 14:00:00 GMT

In a previous blog post by my colleague Tony Robalik, titled Herding Elephants we explored the challenges of managing an expansive Gradle project. At that time, we discussed the complexities faced by Android developers at Square as they navigated a project with over 3,500 modules. Since then, our project has grown even furthe…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Winners of the Square Hackathon for Emerging Technologies

Leher Pathak — Thu, 20 Jul 2023 14:00:00 GMT

Thank you to everyone who participated in the Square Hackathon 2023! This year more than a thousand developers submitted apps built with Square APIs and other emerging technologies. They competed for a grand prize of $20,000 alongside other prize pa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s Updated Growth Framework for Engineers and Engineering Managers

Kyle Van Essen — Wed, 19 Jul 2023 13:00:00 GMT

Four years ago, we shared the Block engineering levels in Square’s Growth Framework for Engineers and Engineering Managers. Right now, four years feels like a lifetime ago! It is probably unsurprising to hear that our levels have seen significant change over the last four years as well to better suit our growing company.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Lessons Learned From Running Web Experiments

Sneha Vasanth — Wed, 05 Jul 2023 05:00:00 GMT

I am a Product Data Scientist for the Ecosystem Discovery team at Square, which helps design, develop, and maintain several key pages of the public website squareup.com. These include the Homepage, Pricing page, Why Square, Point of Sale, etc which have a significant volume of visitors who want to discover and sign up for Square solutions. Due to the substantial traffic volume on these pages, any modifications to them can have a significant impact on downstream metrics and multiple…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Implicit Product Tagging

Alessandro Joabar — Thu, 29 Jun 2023 06:00:00 GMT

Problem Statement

To best understand the problem that Implicit Labeling solves, it’s important to clarify what Explicit Labeling is. Fundamentally, any model needs data X to predict the output Y. For example, given a series of transactions (let’s call these X), we ca…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Keeping Up with Android App Size Growth

Justin Wong — Tue, 27 Jun 2023 06:00:00 GMT

At Square, we build multiple mobile apps spanning low-end to high-end Android devices as well as our own custom Square hardware. As we continue to expand our range of point-of-sale software solutions, a crucial aspect of development is reducing the …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Subscriptions API Integrations with Catalog and Orders

Priscilla Wu — Mon, 26 Jun 2023 17:00:00 GMT

The Subscriptions API allows you to integrate Square Subscriptions into your applications, empowering sellers to drive repeat business and build stronger relationships with customers.

Today, we are thrilled to announce the general availability of two new integrations with Square Catalog and Orders for the Subscriptions API. These integrations create a tighter connection between the Subscriptions API and the broader Square ecosyst…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Unlock a Better Mobile Experience with Square GraphQL and PKCE

Eva Sasson — Mon, 26 Jun 2023 15:00:00 GMT

More secure, faster, and streamlined all around.

Now you can build with Square for an improved mobile experience. Functionally, what has historically been impossible to build (or painstakingly time consuming at best) is now easily accessible to all developers with the releases of GraphQL and OAuth Proof Key for Code Exchange (PKCE)

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Recap: Square Unboxed 2023

Tristan Tyler — Thu, 22 Jun 2023 07:00:00 GMT

We hope you feel inspired after attending Square Unboxed 2023, a partner and developer event. In case you missed it, we heard from Vijay Vachani, General Manager, Global Head of Developers and Partners, and Mike Ward, Head of Product, Developers and…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing New Terminal API Customization Features

Priscilla Wu — Thu, 15 Jun 2023 15:00:00 GMT

The Terminal API allows developers to integrate Square Terminal, our all-in-one card processing device, with their custom point-of-sale, ERP, practice management system, or any other app to process in-person payments.

We are excited to announce the beta launch of Custom Workflows on Terminal API, a new feature empowering developers to create dynamic buyer-facing workflows on the Square Terminal that extend beyond payments. Developers can now incorporate customiza…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Maximizing Solution Visibility with Machine Learning-Powered App Recommendations

Steven Kim — Tue, 13 Jun 2023 08:00:00 GMT

We’re excited to announce the launch of our machine learning-powered App Recommendations!

Sellers often struggle to find the right third-party solution for their businesses. Our research has revealed that sellers not only lack awareness of the different solutions Square offers, but also want guidance in selecting the right solution tailo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Accelerating Ruby: How Our Bundle Install Times Got 12x Faster

Roger Hu — Tue, 23 May 2023 15:00:00 GMT

In 2014, Samuel Giddins, a 19-year old freshman at the University of Chicago, decided to delay returning to college for his sophomore year. Determined to address a glaring deficiency in CocoaPods, an open source tool for managing and installing third-party libraries for i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Connecting Block Business Units with AWS API Gateway

Michael Weissbacher — Thu, 18 May 2023 13:00:00 GMT

Overview

When Block acquires another company, we often want to integrate backend services to benefit from each others’ technology. For example, one can imagine an acquisition wanting to leverage internal APIs, such as Block’s internal payments stack. A naive…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Keeping IDE Sync Times at Bay: A Historical Perspective

Roger Hu — Thu, 04 May 2023 07:00:00 GMT

Ten years ago at Google's I/O 2013 conference, engineering director Tor Norbye unveiled Android Studio, a state-of-art integrated development environment (IDE) for building, testing, and shipping apps. Demonstrating the capabilities of this new tool, Tor showed how it would make developers more productive and efficient. Android Studio…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ecosystem Success Metrics

Daeus Jorento — Wed, 26 Apr 2023 06:00:00 GMT

Square has an integrated ecosystem of over 35 products for sellers (including Online Store, Square Payroll, Invoices, Square for Retail, Loans, and more). For each individual product, there are focused success metrics to prioritize for different product milestones (e.g. free trial starts, first revenue event, etc).

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building Stronger Partnerships as a Data Scientist

Ini Li — Thu, 06 Apr 2023 08:00:00 GMT

I’m a senior data scientist on Square’s Seller Experience team and I work on our online Help Experience. Our team provides relevant and targeted support to sellers at Square, allowing them to spend less time seeking help and more time running their …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Accept Payments with Square and Vue

Anthony Giuliano — Thu, 30 Mar 2023 07:00:00 GMT

If the thought of implementing online payments makes your stomach churn, you’re not alone. Building an online payment flow can be very intimidating. Afterall, an unsecure payment process can have serious repercussions for your business. Luckily, Squ…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Accept Payments with Square and Svelte

Anthony Giuliano — Thu, 30 Mar 2023 07:00:00 GMT

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Why You Need an Experimentation Template

Kasia Rachuta — Thu, 23 Feb 2023 06:00:00 GMT

I have spent almost half of my data career working at Block, starting as an IC, managing people for some time and now as a DS tech lead. I’ve also been on multiple teams here: Developer Empowerment, e-commerce, sales analytics and most recently - at…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Stampeding Elephants

Tony Robalik — Tue, 31 Jan 2023 06:00:00 GMT

Just over a year ago, we published Herding Elephants, in which we explained how we—Square's Mobile Developer Experience (MDX) Android team—successfully modernized the build logic of Square's Point of Sale apps. In that post, we described the rationale for why we did this, and what we thought we gained from the effort (such as better separation of concerns, testability, and ultimately improved performance). That rationale was fairly abstract, however, wit…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: Reference Health

Roberto Annunziata — Tue, 17 Jan 2023 05:00:00 GMT

Today we are going to share a very inspiring story from John Bona, the co-founder of Reference Health. Reference Health is a platform that enables health care providers to accept payments with Square, directly in their electronic medical record (EMR…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Celebrating the release of Android Studio Electric Eel

Roger Hu — Thu, 12 Jan 2023 05:00:00 GMT

Tucked away in the Android Studio Electric Eel release notes is a small announcement about a new parallel project import feature. For most Android app developers on small code bases, this change may not be significant. But for large mobile code bases, especially for ones used at Square, it represents a significant enhancement. For our apps that rely on more than 3,00…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Command Line Observability with Semantic Exit Codes

Bob Lail — Tue, 03 Jan 2023 05:00:00 GMT

Command Line Tools at Square

At Square, many platform teams publish Command Line (CL) tools for interacting with their services. Their customers (Square engineers) use them to search logs, connect to databases, generate code, and more. And because CL tools are particularly easy…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Saving 5,400 hours a year with Gradle's Configuration Cache

Paul Hundal — Tue, 13 Dec 2022 05:00:00 GMT

Have you ever had to wait for some ridiculously lengthy process to validate the completion of your work? This lengthy wait time is something our Android developers can relate to! They could watch 60 back-to-back football games in the amount of time …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Online Payments with Square and React

Anthony Giuliano — Thu, 17 Nov 2022 05:00:00 GMT

If the thought of implementing online payments terrifies you, you’re not alone. Scary as it may be, ensuring that you get paid is the most important part of building an online business. Fortunately, we have taken a lot of the guesswork out of buildi…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

More Square Terminal API features now in GA

Roberto Annunziata — Wed, 16 Nov 2022 11:00:00 GMT

We are happy to announce that Orders Integration, Delayed Capture, and App Fees are now available in GA for Square Terminal API in the U.S. Terminal API is an in-person payments API that connects developer apps built on any platform to Square Terminal for card and contactless payments. These features make it easier for developers to serve sellers with vertical-specific and …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the Winners of the Square Unboxed Hackathon

Bobbilee Hartman — Fri, 14 Oct 2022 04:00:00 GMT

Congratulations to the winners!

Thank you to everyone who participated in Square’s Unboxed Hackathon. This year, we wanted to reward developers for building with what we announced as part of the Unboxed this year. That means if you build using Bookings API, Cash App Pay, Checkout API, or Terminal API. Square has become known primarily for its paym…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Payroll’s Migration from a Monolith to Microservices

Harold Sultan — Wed, 12 Oct 2022 04:00:00 GMT

Imagine a large soccer field with many balls scattered around. There are players whose job it is to scour the field checking in on each ball and determining whether the ball should be kicked or skipped. For each ball that needs to be kicked, the p…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: Jammed

Ginevra Mambretti — Fri, 07 Oct 2022 07:00:00 GMT

Jammed is an online booking platform powering music studios and rehearsal rooms, founded in 2019 by UK-based developer and musician Andy Callaghan after hearing from studio owners that existing software didn’t fit their needs.

Andy realized that rehearsal and recording studios spend too much time manually managing room bookings and cancellations through email and over the phone. He wanted to create a solution to the problems felt by the studio owners he spoke to – time sp…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How We Unified on One Graph at Block

Alex Hancock — Wed, 05 Oct 2022 19:00:00 GMT

At Block we are working with federated GraphQL to enable clients to consume a unified API of aggregated data from microservices in the backend. It allows, for example, for a single HTTP request from a client application to fetch data about merchants…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

First Annual Bazel-iOS Con 2022

Jerry Marino — Mon, 12 Sep 2022 07:00:00 GMT

Square will be hosting the first annual Bazel-iOS conference — an open developer event for people building iOS applications with Bazel. You’re invited to join us for a day of iOS build talks, discussion groups, and panels with the Bazel-iOS core tea…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: KioskBuddy

Priscilla Wu — Wed, 31 Aug 2022 19:00:00 GMT

We’re back with another installment of our Developer Spotlight series, where we share the stories and experiences of developers, tech leaders, and entrepreneurs building on the Square platform. In this round, we sat down with Marvin Trajano and Lisa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: Payable Forms

Joan Mweu — Fri, 29 Jul 2022 19:00:00 GMT

Welcome to our Developer Spotlight series, where we highlight developers building on the Square platform. In this installment we speak with Ryan May, the founder and Lead Developer at Payable Forms.

He previously worked as an engineer helping big brands all over the world integrate payments into their business. Since launching their app, Payable Forms has had 200,000 downloads and helps move 6-10 million dollars per month in payments. We asked …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Success Metrics for Product Analytics

Daeus Jorento — Wed, 06 Jul 2022 19:00:00 GMT

Why do we use primary success metrics for product launches? Two reasons: (1) to align with the broader company goals (i.e. to make sure we're not rowing in different directions), and (2) to determine the effect of a product change relative to what w…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Terminal API Beta Features Now Available

Leher Pathak — Thu, 26 May 2022 19:00:00 GMT

We recently released new beta features for Square Terminal API, an in-person payments API that connects developer apps built on any platform to Square Terminal for contactless and card payments. As of today, hundreds of developers have integrated with Terminal API, enabling thousands of sellers to take payment…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Gift Cards API

Priscilla Wu — Fri, 17 Jun 2022 19:00:00 GMT

Many businesses run gift card programs as a way to attract new customers and increase sales. With Square Gift Cards, we enable sellers to launch a complete gifting program with online and physical gift cards that seamlessly integrate into their Squa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Cash App Pay for Developers

Leher Pathak — Thu, 19 May 2022 17:00:00 GMT

We’re thrilled to announce that developers and partners can now add Cash App Pay to their online checkout flow with Square Web Payments SDK and Square Checkout API. Cash App is a popular mobile payment app listed as the #1 finance app in the App Store with more than 70M annual active users in the U.S. Cash App Pay is a new paym…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Unboxed Hackathon 2022

Bobbilee Hartman — Thu, 12 May 2022 17:15:00 GMT

Our latest hackathon – Square Unboxed Hackathon 2022 — is now live! To continue the excitement of everything that we've announced at Unboxed 2022, we want to reward developers for building with what we announced as part of the Unboxed this year. That means if you build using Bookings API, Cash App P…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Reintroducing Checkout API

Joan Mweu — Thu, 18 Aug 2022 19:00:00 GMT

We’re excited to announce an updated version of Checkout API, now in general availability. This version delivers a number of new robust features. Now, you can integrate payments into any workflow and any channel with minimal coding through a conver…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Build With Bookings API, Now Generally Available

Amanda Lee — Tue, 24 May 2022 19:00:00 GMT

In December 2020 we released Bookings API in beta to extend the capabilities of Square Appointments — our point of sale for scheduling, bookings, and payments — to any third-party software. Since the beta launch, we’ve been close to the developer community, gathering meaningful feedback and working hard to deliver a feature-rich API that lives up…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Recap: Square Unboxed 2022

Sneha Patel — Fri, 13 May 2022 17:00:00 GMT

We hope you feel inspired after attending Square Unboxed 2022, our sixth annual Developer Platform conference. In case you missed it, we announced new products: Cash App Pay for developers, Bookings API in general availability, the reinvented Checko…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Coming Up: Square Unboxed 2022

Sneha Patel — Mon, 18 Apr 2022 19:00:00 GMT

We are so thrilled to host the 6th annual Square Unboxed - our developer and partner conference - on May 12, 2022! This year's event will be virtual, and we’re embracing all that’s different in this new world of commerce with buy now / pay later, cr…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

DependenTree, Graph Visualization Library

Amogh Kambale — Wed, 23 Mar 2022 19:00:00 GMT

DependenTree is a visualization library that allows users to visualize large dependency graphs as a tidy tree. It is built on top of D3.js.

At Block, we have over 14,000 ETLs. Understanding the data lineage of any given ETL was a tedious task. This involved a combination of gathering information about an individual ETL and examining source code. Previous attempts to visualize this data …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

API and Webhooks Logs Are Generally Available

Chris Lopez — Wed, 09 Feb 2022 18:00:00 GMT

Square has continued to develop tooling to make it easier to build applications that integrate with the Square Developer platform. The latest tool, API Logs, was released in beta at Square Unboxed. API Logs has now graduated from Beta to Generally A…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Afterpay "Buy Now, Pay Later" Now Available

Leher Pathak — Wed, 16 Feb 2022 20:00:00 GMT

We’re excited to announce that Square now offers the ability for developers and partners to integrate Afterpay into their online checkout flow through the Square Web Payments SDK. Afterpay is a global leader in the buy now, pay later (BNPL) space with

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Getting Square's iOS build ready for Apple Silicon with Bazel

Jerry Marino — Thu, 27 Jan 2022 20:00:00 GMT

Introduction to iOS at Square

At Square we use Bazel to build our iOS applications. Bazel is a build tool with an emphasis on performance and correctness. Most of our iOS app code lives in a single git repository. The repository includes over one thousand modules, contains Objec…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Launches in Spain

Karen Faughnan — Tue, 25 Jan 2022 18:00:00 GMT

Square continues its European expansion with today’s launch in Spain offering a full stack of integrated business tools along with its developer platform. Following a successful Early Access Programme that began last September, now all merchants, enterprises, and developers across Spain can access the Square ecosystem with the tools and APIs that they need to start, run, grow, and adapt their businesses.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Secure Apache Airflow Using Customer Security Manager

Yifei Sun — Wed, 19 Jan 2022 20:00:00 GMT

Background

Apache Airflow is an open source orchestration tool to programmatically author, schedule and monitor workflows. Square uses it as a critical infrastructure managing ETL jobs to aggregate metrics for executive dashboards, product analysis, and machine learning.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the winners of the Build What’s POS_sible Hackathon

Shaziya Bandukia — Fri, 17 Dec 2021 19:00:00 GMT

Thank you to everyone who participated in Square’s first-ever Build What’s POS–sible hackathon. This year, participants got to build innovative applications using at least one of our customer solution APIs, including Customers, Gift Cards, Invoices, Loyalty and Team Management. Square has become known primarily for its payments and point-of-…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

An Overview of Machine Learning Operations

Erin Wolpert — Tue, 30 Nov 2021 20:00:00 GMT

What is MLOps?

Starting in 2018 the term “MLOps” (short for Machine Learning Operations) started to be used more widely to describe the discipline of standardizing and streamlining the machine learning lifecycle management process. MLOps advocates for bringing CI/CD practices into the machine learning lifecycle. MLOps lies at the intersection of data engineering, machine learning, and development operations.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Herding Elephants

Tony Robalik — Thu, 04 Nov 2021 11:00:00 GMT

Note: please do not attempt to herd any actual elephants

Every day in Square's Seller organization, dozens of Android engineers run close to 2,000 local builds, with a cumulative cost of nearly 3 days per day on those builds. Our CI system runs more than 11,000 builds per day, for a cumulative total of ov…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Beyond Mobile First

Ryan O'Neill — Thu, 04 Nov 2021 09:00:00 GMT

Since its introduction around 2010, the concept of mobile first web design has become the de facto standard when creating new websites or web applications. The mobile first concept is especially prevalent in the e-commerce industry because over 70% of e-commerce

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Square Build What’s POS-sible Hackathon

Shaziya Bandukia — Tue, 05 Oct 2021 17:00:00 GMT

Our latest hackathon – Build What’s POS-sible — is now live! While Square has become known primarily for its payments and point-of-sale solutions, there’s so much more. Today, we have APIs that span across every aspect of a business, including customer solutions such as Customers, Gift Cards, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Measure, measure, measure

Ralf Wondratschek — Tue, 28 Sep 2021 19:00:00 GMT

How long does it take to implement new features? This is an important metric when it comes to improving the effectiveness of software engineers and will give the company an advantage over its competitors. There are many dimensions to consider, such …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Server-to-Server Integration with Server-Side Google Tag Manager

Amogh Kambale — Thu, 23 Sep 2021 19:00:00 GMT

Last August, Google released Server-Side Tagging in Google Tag Manager 360. Though this platform is considered a “Tag Manager” and is conceptually similar to the web container, the implementation is entirely different. Server side tags are simply API endpoints for each marketing vendor that can be configured using the fam…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Launches in France

Karen Faughnan — Tue, 21 Sep 2021 15:00:00 GMT

Today Square launched in France! This marks the second European country that Square has launched with a full stack of integrated business tools along with its developer platform. Following a successful Early Access Programme, now all merchants, enterprises, and developers across France can access the Square ecosystem with the tools and APIs that they need to start, run, grow, and adapt their businesses.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Chrometric: System telemetry for Chrome OS

Nate Walck — Tue, 31 Aug 2021 19:00:00 GMT

When it comes to managing Chrome OS in a distributed work environment one of the biggest challenges is understanding how well Chrome OS is performing and the health of the network environment it finds itself in.

Chrometric is a Chrome OS extension which gathers key telemetry about your Chrome OS machines. These metrics are important to understand as they give insight into what the user is experiencing as well as the network conditions of the current locatio…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

AWS OIDC Authentication with SPIFFE

Roy Xu — Thu, 26 Aug 2021 19:00:00 GMT

As part of Square’s migration to the cloud, we found that we needed an easy way for our datacenter applications to communicate with services in AWS. A majority of our applications are still in the datacenter and often use services in AWS such as SQS…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Kotlin-Multiplatform Shared Test Resources

Victoria Gonda — Tue, 24 Aug 2021 19:00:00 GMT

A usual test strategy is to have test fixture files, be it JSON, binary, or plain text files, to consume in tests. You may use these files for test input, test verification, or both. Using this strategy with Kotlin Multiplatform (KMP), you can ensur…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Why Workflow?

Stephen Edwards — Thu, 19 Aug 2021 21:00:00 GMT

Last week you heard from Zach Klippenstein about using Jetpack Compose with the Workflow library. You may be asking why Square uses Workflow at all!? We ask ourselves this sometimes too — because it is always good to evaluate the tools you use. This post reflects on that question.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Upgrading Webpack 4 → 5

Hiroki Osame — Wed, 18 Aug 2021 23:00:00 GMT

Webpack 5 was released last year in October. We had been hearing many great things about it in the Ecommerce department at Square, but had been reluctant to go through the upgrade work.

Upgrading developer tools is usually not pressing, can be time consuming, and modifying a bundler can be high risk. Since we rely on a few Webpack plugins, it also made sense to give the ecosystem time to adapt to the breaking changes. We also read it might be slower

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Subscriptions API is Generally Available

Shaziya Bandukia — Wed, 11 Aug 2021 19:00:00 GMT

We’re thrilled to announce the general availability of Subscriptions API. Plus, after hearing from our developers, we learned there was a strong need to be able to manage subscriptions on the backend–this is now available through the Subscriptions a…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Jetpack Compose Support in Workflow

Zach Klippenstein — Tue, 10 Aug 2021 19:00:00 GMT

Abstract

Square’s mobile Point of Sale apps are largely built using a library called Workflow, on both Android and iOS. We write business logic as declarative state machines, and then build our UI on top of them using the target platform’s UI toolkit — Views on Android.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Square Unboxed Hackathon Winners

Elsie Phillips — Wed, 04 Aug 2021 19:00:00 GMT

Square Unboxed is always an exciting time of year here at Square. For months leading up to the event product teams work to prepare their exciting announcements for the big stage. While we were preparing the announcements we came up with an idea: wha…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Threat Hunting with Kubernetes Audit Logs - Part 2

Ramesh Ramani — Tue, 17 Aug 2021 19:00:00 GMT

Welcome back! If you have arrived here, I assume you have a fair understanding of how Kubernetes audit logs can be useful from the previous article. Now let us dive in a bit deeper and see how we can use these audit logs to hunt for attackers using the MITRE ATT&CK® framework.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Threat Hunting with Kubernetes Audit Logs

Ramesh Ramani — Tue, 03 Aug 2021 19:00:00 GMT

From the official Kubernetes page - “The core of Kubernetes' control plane is the API server... The Kubernetes API lets you query and manipulate the state of API objects in Kubernetes (for example: Pods, Namespaces, ConfigMaps, and Events)”.

The Kubernetes API is quite powerful and malicious actors can use the API to attack a Kubernetes cluster. The Kubernetes audit logs provide visibility into what an attacker is trying to do by providing a clear audit trail of the API calls made to th…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Expanding Secrets Infrastructure to AWS Lambda

Michael Weissbacher — Wed, 04 Aug 2021 19:00:00 GMT

Overview

This article describes how we extended our Data Center (DC) based secrets infrastructure to enable cloud migration supporting Lambda. We added SPIFFE compatibility to our secrets infrastructure and developed a Lambda secrets syncer that Square engineers can deploy via a Terraform module. Our design choices aim to offer the best of both worlds: easy management via an established centralized syste…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Deploying Server-Side Google Tag Manager on Cloud Run

Amogh Kambale — Thu, 15 Jul 2021 21:00:00 GMT

Server-Side Google Tag Manager (server-side GTM) is a new product from Google Marketing Platform. It moves marketing event processing off the user’s browser to a backend server that you control.

The standard deployment method for server-side GTM consists of automatically setting up an App Engine Flexible application. App Engine is a fully-managed platform-as-a-service deployment solution from Google Cloud Platform (GCP). Users can provision a server by filling out a form in Google Tag Mana…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

WorkManager for Background Work in Libraries

Stephen Edwards — Wed, 21 Jul 2021 19:00:00 GMT

WorkManager is an Android Jetpack library for deferrable, reliable background work. In other words, the work does not need to be run immediately, but it must be run reliably (even after the app process restarts), and it is usually run off the main thread.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Becoming an Organizational Leader

Michael Ortali — Tue, 13 Jul 2021 19:00:00 GMT

As your career progresses, it can become increasingly difficult to understand how to move up the ladder as an individual contributor. Extending on our "Square’s Growth Framework for Engineers", we are now sharing in depth what it means to grow from being a team leader (Level 6) to being an organizational leader (Level 7), specifically focused on the journey for individual contributors.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Gift Cards API

Shaziya Bandukia — Wed, 16 Jun 2021 19:00:00 GMT

Gift cards provide gift-givers the ultimate flexibility when making purchases for a loved one, while recipients are empowered with choice and potentially, an easy payment method. Plus, gift cards help sellers bring in new customers and drive increme…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Cards API

Leher Pathak — Wed, 16 Jun 2021 19:00:00 GMT

A seamless buyer experience starts at checkout. Nothing says “poor experience'' like asking a buyer to rummage for their credit card every time they shop at their favorite store. With the Cards API, you can now store, retrieve, and manage credit and…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Caching E-Commerce Data for The Web

Sebastien Armand — Wed, 26 May 2021 16:00:00 GMT

The catalog service

The Square Online catalog service provides all the catalog data for the websites we power. This includes products, categories of products, store locations, and many others.

While some catalog data is fairly simple to present in an API response, other parts are more costly to calculate. The price of a product, for example, comes from many sources: SKUs (think a Small vs. Large shirt), modifiers (would you like cheese …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Loyalty API is Generally Available

Shaziya Bandukia — Thu, 20 May 2021 19:00:00 GMT

We’re excited to announce that Loyalty API is now generally available. Square Loyalty API enables developers to extend the intuitive Square Loyalty rewards program beyond Square’s Point of Sale, Square Online and Cash App to third-party channels–off…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Web Payments SDK and ACH Beta

Leher Pathak — Thu, 20 May 2021 03:00:00 GMT

The eCommerce industry is booming. According to a recent study by Digital Commerce 360, consumers spent approximately $861 billion online with U.S. merchants in 2020. That’s the highest annual U.S. eCommerce growth in at least two decades and this trend is not going away any time soon. While businesses scrambl…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Launches in Ireland

Marylise Tauzia — Tue, 18 May 2021 19:00:00 GMT

Today Square launched in Ireland! Following a successful Early Access Programme, now all merchants, enterprises, and developers across Ireland can access Square’s innovative ecosystem with the tools and APIs that they need to start, run, grow, and adapt their businesses.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Snippets API: The first API for Square Online

John Elliott — Mon, 17 May 2021 10:00:00 GMT

Thousands of sellers are signing up to create websites every day on Square Online. The transition to selling online and developing an omnichannel strategy is top of mind for most entrepreneurs. As they set up their sites and build their online prese…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Recap: Square Unboxed 2021

Marisa Almeida — Fri, 14 May 2021 16:00:00 GMT

We announced two new ways to integrate with Square, brought a Beta API to General Availability, and kicked off a hackathon. And now we’re here to recap it for you.

We hosted our fifth annual developer and partner conference on May 13. It was so energizing to connect with our community. We all got a chance to hear from Square platform leadership, participate in demos and workshops, learn from developers who hav…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Invoices API is Generally Available

Shaziya Bandukia — Wed, 21 Apr 2021 19:00:00 GMT

After a few months in beta, we’re thrilled to announce that Invoices API is now generally available. Since the early days of Square, our vision has been to combine the collective force of our seller-first platform with the power of extensibility fro…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Curtains

P-Y Ricau — Fri, 05 Mar 2021 20:00:00 GMT

On Android, every distinct floating thing you see on your device is managed by a distinct window. Every activity, every dialog, every floating menu, every toast (until Android Q), the status bar, the notification bar, the keyboard, the text selectio…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Authorization Tooling – Improved Usability and Security

Mike Ward — Wed, 16 Dec 2020 20:00:00 GMT

As our developer ecosystem continues to expand, our partnering developer needs have pushed us to improve our Authorization tooling for a better and more secure experience. This update covers three OAuth Access Token improvements which can be used in…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Bookings API Beta

Leher Pathak — Wed, 16 Dec 2020 08:00:00 GMT

Hair salons, massage spas, and tattoo parlors all have one thing in common—they rely on appointments software to run their business. With Square Appointments, businesses can create a free online booking website that manages scheduling, staffing, inventory, customers, and payments in a single point of sale. Square Appointments simplifies day-to-day operations by enabling automated appointment reminders, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Wiring Libraries with Cleanse

Sebastian Shanus — Wed, 02 Dec 2020 20:00:00 GMT

Cleanse is a Swift dependency injection framework we introduced in 2016. Since then, we’ve added several new features and it continues to be a tool that our developers enjoy using to reduce boilerplate and configure their dependency graphs.

Even with these benefits, we’re always looking for better ways to leverage the power that comes with Cleanse. Today, we’ll discuss how extracting our bindings, modules and components into what we call "wiring libraries" has given us greater control …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the New Square Node.js SDK

Richard Moot — Wed, 18 Nov 2020 20:00:00 GMT

We’re excited to announce our new Node.js SDK is now available in General Availability! This new square package is a major update that adds TypeScript support and replaces the deprecated square_connect package. With JavaScript codebases you can now get type-based hints from your IDE or text editor and with TypeScript codebases you can get full type checking for your SDK usage.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Square Online Agency Program

John Elliott — Wed, 28 Oct 2020 19:00:00 GMT

Over the last quarter there has been a 6x increase in the number of sellers on Square Online, and 25% of Square’s GPV is now from online sales. There is now a bigger need to help sellers as they continue to transition to an omnichannel sales strateg…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Build with Square Terminal API, Now Generally Available

Leher Pathak — Thu, 15 Oct 2020 18:30:00 GMT

Developers and partners building on Square’s platform are rising to the occasion to help businesses safely return to in-person commerce. As we redefine a new normal, businesses can leverage solutions like self-ordering kiosks and order-ahead apps to…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using AWS Lambda Extensions to Accelerate AWS Secrets Manager Access

Michael Weissbacher — Thu, 08 Oct 2020 17:00:00 GMT

This was a collaboration between Michael Weissbacher from Security Infrastructure and Michele Titolo from Cloud Foundations.

Overview

AWS Lambda Extensions are a new way for tools to integrate deeply into the Lambda environment, and they can run before the start of a Lambda function. This allows us to perform preparatory tasks that are only necessary on a cold start for example. W…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing OAuth Revocation Webhook Events

Mike Ward — Wed, 16 Sep 2020 19:00:00 GMT

Developers have struggled to navigate failed API calls when revoked access tokens are used, while not understanding which merchants unsubscribed to their application. We recently filled this gap, and are excited to announce the release of OAuth Revo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Radiography

Zach Klippenstein — Fri, 04 Sep 2020 18:00:00 GMT

As Android developers, a large part of our job is ultimately to show pixels on people’s devices. The rest of our job is making those pixels do something when you touch them. Despite this simple goal, getting the right pixels to show up can sometimes be a challenge. When something goes wrong and your views don’t look like they should, it’s helpful to be able to peek behind the curtain to see what the views are actually doing. When you can connect a debugger to yo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square Unboxed 2020

Marisa Almeida — Wed, 02 Sep 2020 19:00:00 GMT

We’re thrilled to be announcing that Square Unboxed, our annual developer and partner conference, is happening – virtually – this year. Registration is now open for the free, 90-minute event on October 15. Register by September 28 to secure your spo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Employees, OAuth, Orders, Reporting, and Inventory APIs

Richard Moot — Wed, 26 Aug 2020 19:00:00 GMT

We’ve had a lot of APIs coming out, with Subscriptions, Invoices, Team Management, Loyalty, and Terminal API, it's nice to take a chance to dig in on some of the smaller but important changes to the Square API. With the latest API release on August 26th, we’ve added in some new functionality for OAuth webhooks and made some changes to Employees, Orders, R…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Providing mTLS Identities to Lambdas

Michael Weissbacher — Tue, 25 Aug 2020 19:00:00 GMT

Overview

This article describes how Square issues identity to applications in AWS Lambda so they can make authenticated calls to applications running in our data center, and why we chose mutual TLS to do so. A previous post describes how we use AWS Lambda at Square on a high level, while diving into security aspects here.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Square App Marketplace Ratings and Reviews

John Elliott — Mon, 17 Aug 2020 19:00:00 GMT

In order to continuously launch products that sellers want, teams need feedback from multiple channels to improve their product. Square App Marketplace ratings and reviews provide a new feedback channel to gather insights while giving sellers a way …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Subscriptions API Beta

Leher Pathak — Wed, 12 Aug 2020 19:00:00 GMT

From monthly wine deliveries to virtual fitness memberships, subscriptions have become a popular way for businesses to handle no-contact commerce. Despite the recent impact to our global economy, the subscriptions market has stayed relatively stable…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The State of Ruby 3 Typing

Soutaro Matsumoto — Wed, 29 Jul 2020 19:00:00 GMT

We're pleased to announce Ruby 3’s new language for type signatures, RBS. One of the long-stated goals for Ruby 3 has been to add type checking tooling. After much discussion with Matz and the Ruby committer team, we decided to take the incremental …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Invoices API Beta

Leher Pathak — Wed, 22 Jul 2020 18:00:00 GMT

For freelancers, contractors, caterers, and other businesses, maintaining a steady cash flow is more important than ever. One of the easiest ways to bill, record, track, and get paid for goods and services quickly is through an invoice. With invoice…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Square Small Business Hackathon Winners

Elsie Phillips — Fri, 17 Jul 2020 19:00:00 GMT

The last few months have been challenging for businesses of all sizes. In the wake of shelter-in-place orders, entrepreneurs have needed to adapt their businesses and weather the economic storm. We knew that sellers would need technology solutions t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using Amundsen to Support User Privacy via Metadata Collection at Square

Alyssa Ransbury — Tue, 14 Jul 2020 19:00:00 GMT

When I started at Square, one of our primary privacy challenges was that we needed to scale and automate insights into what data we stored, collected, and processed. We relied mostly on manual work by individual teams to understand our data. As a co…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Enabling Serverless Applications at Square

Michele Titolo — Wed, 08 Jul 2020 19:00:00 GMT

Square and the Cloud

Square is early in its migration to the cloud and most applications run in our datacenters today. The Platform and Infrastructure Engineering (PIE) organization has historically focused on providing infrastructure and tooling to build and operate in…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Manage Team Data from Any Platform with Square Team API

Leher Pathak — Thu, 25 Jun 2020 19:00:00 GMT

This year, businesses made the difficult decision to reorganize their teams as they faced financial challenges and shifting business models. Now, as businesses begin to reopen, business owners need an easy and reliable way to make employees’ return …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Anvil

Ralf Wondratschek — Tue, 23 Jun 2020 19:00:00 GMT

Our Point of Sale Android codebase is a large modularized repository consisting of thousands of Gradle modules and hundreds of applications, each with its own unique Dagger 2 dependency graph. When creating a new application, one of the biggest bottlenecks we’ve seen in developer productivity was setting up Dagger dependencies. It’s a tedious process and involves many steps:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

API Explorer Moves to General Availability

Elsie Phillips — Tue, 16 Jun 2020 19:00:00 GMT

Today we’re announcing the general availability of the API Explorer after its beta release in December 2019. Developers can use the API Explorer to test endpoint behaviors for all publicly available v2 APIs. They can do this within the browser without having to implement any code or update environment configuration…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square’s New PHP SDK

Richard Moot — Wed, 10 Jun 2020 19:00:00 GMT

We’re excited to announce our new PHP SDK. You can use the SDK to integrate Square payments into your app. Run your business with Square APIs including Catalog, Customers, Employees, Inventory, Labor, Locations, Orders, and more.

There are a few ways to install the Square package.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Reward Customers Wherever They Shop with Loyalty API and Customers API

Leher Pathak — Thu, 28 May 2020 19:00:00 GMT

Earning customer loyalty is critical in this unprecedented time as businesses try to stay afloat with the support of their customers. One of the ways to maintain a strong customer relationship is through a loyalty program, whether it’s offering a fr…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Square Small Business Hackathon

Elsie Phillips — Wed, 20 May 2020 19:00:00 GMT

The world has changed a lot in just a few short months. Many business owners must completely rethink how they do business. We want to make it as easy as possible for them to make the pivot to contactless commerce and adapt to this challenging new …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Kubernetes - Pod Security Policies

Jason Price — Thu, 07 May 2020 19:00:00 GMT

My team is building a general purpose kubernetes cluster at Square. As a part of that build out, we implemented Pod Security Policies (PSPs) to protect our clusters from many container escape risks.

This post is focused on how to do a full deployment of Pod Security Policies with everything locked down and how to grant exceptions. For an introduction to PSPs, please go read the Official Kubernetes PSP documentation. The official documentation does a good job of showing how to use a simple PSP example, however fails in describing how a fully functioning PSP system would work, how it would be applied by default, and how exceptions could be managed. This post w…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Creating Custom Attributes in Catalog

Leah Walkiewicz — Tue, 05 May 2020 19:00:00 GMT

With an ever-increasing demand for contactless commerce, Square sellers have asked for help growing their digital sales. Sellers rely on the Catalog API to help them represent what they’re selling accurately, in whatever channel they make a sale. Fo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Touch-free Commerce Application Guides

Elsie Phillips — Thu, 30 Apr 2020 19:00:00 GMT

Sellers right now are looking for solutions to help them run their business in this new environment. They need help taking their businesses online and navigating touch-free commerce. To help address this, we’ve created a new section on the Square Ap…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Curbside Pickup in the Orders API

Chada Saetie — Tue, 28 Apr 2020 19:00:00 GMT

In these unprecedented times, sellers must react to the rapidly changing business environment to survive and even thrive. This means enabling new fulfillment types, including those that reduce in-person interaction. That’s why today, we’re announcin…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Resources for Getting Started

Elsie Phillips — Fri, 24 Apr 2020 19:00:00 GMT

We know how important it is to be able to quickly and easily find the information you need as you build applications for your users and your clients. For the last several months we’ve been working to make our developer sites and the dashboard more u…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square Terminal API Beta

Leher Pathak — Wed, 22 Apr 2020 19:00:00 GMT

Now more than ever, it's critical to develop a POS solution that adapts to new ways of running a business. Whether you're developing a custom-built kiosk for ordering and checkout, or a medical practice management system to synchronize patient data,…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Android In-App Payments SDK Tutorial

Bobbilee Hartman — Tue, 24 Mar 2020 19:00:00 GMT

I’ll be walking you through our Android In-App Payments SDK so you can implement a secure, customizable payment form in your mobile app. We also have plugins for this SDK that support Flutter and React Native, which you can learn about by watching our other videos

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Dessa: Open sourcing Atlas

Stephen Piron — Tue, 17 Mar 2020 19:00:00 GMT

This is a post from Dessa, an applied deep learning company that became part of the Square ecosystem in February 2020.

Just a month after joining Square, today we’re excited to announce the open source launch of Atlas, a tool for developing applied deep learning projects.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: AuctionZoom

Richard Moot — Thu, 12 Mar 2020 19:00:00 GMT

We're back, with another round of our Developer Spotlight series, where we highlight developers building with Square. In this installment we spoke with John Foster, CEO of AuctionZoom. We asked him about his company’s experience building with Square, what kinds of problems they’re solving for merchants, and what led them to choose Square.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Disputes API

Leher Pathak — Tue, 10 Mar 2020 19:00:00 GMT

Customer disputes can be frustrating for sellers. Sellers may have to manage numerous chargebacks at once, or need to submit multiple forms of evidence to challenge disputes. Until recently, sellers had to do this manually through their Square Dispu…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Labor, Bank Accounts, & CashDrawerShifts V2 APIs

Richard Moot — Wed, 26 Feb 2020 20:00:00 GMT

This month we have several really great updates and releases. The V1 Timecards API functionality is now supported in the V2 Labor API. This change brings in more flexible models for handling shifts, recording time zones, and also V2 Webhook support.

We have also released our V2 CashDrawerShifts and V2 Bank Accounts APIs. CashDrawerShifts lets you easily manage cash drawer activity for creating bookkeeping reports for cash drawers paired with a Square Point of Sale. The Bank Accounts API allows …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Showing the Android Keyboard Reliably

Helios Alonso — Tue, 25 Feb 2020 20:00:00 GMT

When we develop our Android applications, the keyboard is something we rarely think about. It’s a service provided by the platform and it’s crucial it’s that way. It conveys so much functionality and covers so many cases that it would be nearly impo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Card on File with React Native

Richard Moot — Thu, 19 Mar 2020 20:00:00 GMT

In this tutorial, we’ll show you how to accept payments in a React Native application using Square’s In-App Payments SDK and React Native plugin. I’ll also show you how to safely store customer card details so that they don’t have to be manually re-entered or re-swiped for future transactions.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Instrumenting Firebase Test Lab

P-Y Ricau — Wed, 15 Jan 2020 20:00:00 GMT

At Square, we rely heavily on automated testing to ensure that our applications work well. Our Point of Sale Android codebase is just shy of 1.5 million lines of code, and we run about 6000 Android instrumentation tests on Firebase Test Lab on every pull request

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Adopting AWS VPC Endpoints at Square

Harihara Krishnan Narayanan — Fri, 20 Dec 2019 20:00:00 GMT

In this post, we share our experiences with adopting AWS VPC Endpoints at Square. We want strong security guarantees in our communication with managed AWS services and for that we designed a solution that leverages VPC Endpoints with IAM policies. In a later section, we also highlight some of the issues we faced in our setup and usage of these endpoints.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square’s New Java SDK

Shannon Skipper — Wed, 18 Dec 2019 20:00:00 GMT

We’re very pleased to announce our new Java SDK. You can use the SDK to integrate Square payments into your app. Run your business with Square APIs including Catalog, Customers, Employees, Inventory, Labor, Locations, Orders, and more.

To install the package, just run

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square’s New .NET SDK

Shannon Skipper — Tue, 17 Dec 2019 20:00:00 GMT

We’re excited to announce our new .NET SDK. You can use the SDK to integrate Square payments into your app. Run your business with Square APIs including Catalog, Customers, Employees, Inventory, Labor, Locations, Orders, and more.

There are a few ways to install the Square package.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Sandbox & Locations Now Generally Available

Richard Moot — Wed, 20 Nov 2019 20:00:00 GMT

Sandbox & Locations API move to General Availability

With our 2019-11-20 API release, we have officially moved Sandbox out of beta and into general availability (GA). Additionally, we have moved the RetrieveLocation and ListLocations endpoints of the Locations API from beta to GA. As a result of this release and moving endpoints into GA, we are also announcing some endpoints that are being deprecated. You can find more about our deprecation policy in our docs, along with a sche…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Developer YouTube

Richard Moot — Wed, 06 Nov 2019 20:00:00 GMT

We’d love nothing more than to meet developers in person, no matter where in the world they might be. Unfortunately, our accounting department says that would be impractical. So instead we’ve decided to try to meet you all digitally by creating a ne…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the Square Partner Community

Peter Parker — Thu, 17 Oct 2019 19:00:00 GMT

Today, we are excited to announce the launch of the Square Partner Community, continuing our investment in Square’s partnerships. The Square Partner Community gives Square Partners, including digital agencies and system integrators, access to traini…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Books, an immutable double-entry accounting database service

Łukasz Strzałkowski — Wed, 16 Oct 2019 07:00:00 GMT

Square in 2019 looks very different from when we launched almost 10 years ago. We now have at least half a dozen totally independent products, from Caviar, Capital, to the Cash App. As we have scaled our financial infrastructure and moved beyond sim…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Webhook Event for Syncing with Square Catalog

Leah Walkiewicz — Thu, 03 Oct 2019 19:00:00 GMT

We’re excited to share the new and improved webhook event for updates to Square Catalog, called CatalogVersionUpdated. CatalogVersionUpdated is a new webhook event available that helps developers stay in sync with a seller’s catalog and better maintain their omnichannel integrations.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Open Source Code of Conduct

Square Engineering — Tue, 27 Jan 2015 17:08:00 GMT

At Square, we are committed to contributing to the open source community and simplifying the process of releasing and managing open source software. We’ve seen incredible support and enthusiasm from thousands of people who have already contributed t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Discounting at Square

Tad Book — Wed, 04 Sep 2019 19:00:00 GMT

Square recently launched a set of flexible APIs to create auto-apply discounts. I wanted to take some time to explain how they work, why we designed them the way we did, and how they can be used to implement a wide variety of discounting schemes.

The Model

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Item Options for the Catalog API

Leah Walkiewicz — Wed, 28 Aug 2019 19:00:00 GMT

Previous versions of the Catalog API modeled products for sale as items and item variations. An item represents a product that may be sold while an item variation represents the actual object being sold, typically with distinct name, description, SK…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square’s New Python SDK

Richard Moot — Tue, 27 Aug 2019 19:00:00 GMT

We’re excited to announce the release of our new Python SDK. Run your business with Square APIs including Catalog, Customers, Employees, Inventory, Labor, Locations, Orders, and more.

To install the Python SDK, just pip install squareup from the command line. You can alternatively clone the SDK from GitHub and install it using python setup.py install --user . Next, all you need to do is provide your access token and you’re ready to use Square APIs.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New and Improved Sandbox

Brian Gorby — Thu, 22 Aug 2019 19:00:00 GMT

Developers building on the Square platform now have a powerful new tool available to help them more quickly build, test, and deploy their omnichannel integrations. We’re thrilled to announce a brand-new version of our Sandbox, now available in beta.

In talking with developers looking to build applications for Square sellers, we heard three consistent themes of how we could improve the Sandbox experience: full coverage of Connect v2 APIs, the ability to quickly create testing accounts to simulat…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Manage Orders from Anywhere

Chris Wiggins — Wed, 21 Aug 2019 19:00:00 GMT

The Orders API provides developers the means to create and read itemized sales within Square. Now developers can leverage new endpoints to update, manage, and pay for Orders, extending the possible use cases. UpdateOrder (Beta) allows itemizations, discounts, taxes, and fulfillment data to be updated on an open order.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the new Square Payments API

Chris Heisel — Tue, 20 Aug 2019 19:00:00 GMT

I’m excited to share the new and improved API for taking payments online and in-app - the Payments API launches today!

This new API replaces the Transactions API and launches with key new features like:

Paying with a Square Gift Card
Paying for an order with multiple payments
Collecting tips at time of payment
Providing additional information about CVV and AVS statuses, as well as improved card decline reasons
Simplified payment interface: location ID management is not required for creating or refunding payments

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Expanding Square’s Platform Beyond Payments

Marylise Tauzia — Thu, 15 Aug 2019 16:00:00 GMT

Today, we are excited to announce a significant expansion of the Square platform to include a new set of APIs and SDKs that developers can leverage to build customized and scalable commerce experiences.

Over the past couple of years, we’ve released APIs and SDKs that focus on enabling developers to take payments in person, online, and in mobile apps. We’re now expanding our platform and shifting the focus from payments to orders. Orders are now a central component of our platform as they connect payments to items, price modifiers, customers, and more.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: Postmates

Richard Moot — Wed, 14 Aug 2019 10:00:00 GMT

In working with Postmates on their integration of the Square Orders API, we wanted to sit down with them and chat a little more about what Postmates is up to and how that process went. For those unfamiliar, Postmates is a logistics platform that connects customers with local couriers who can deliver anything from any s…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Chasing Swallowed Exceptions

Ralf Wondratschek — Tue, 13 Aug 2019 19:00:00 GMT

Tests are an essential part of every software project. They give developers confidence that any change they make doesn’t break existing functionality. A test is either successful if the assumptions pass the requirements, or unsuccessful if a verific…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Shark: Smart Heap Analysis Reports for Kotlin

P-Y Ricau — Tue, 06 Aug 2019 19:00:00 GMT

Recently I just released LeakCanary 2 Beta 1, and with it a new standalone library: Smart Heap Analysis Reports for Kotlin, aka Shark.

Shark is the heap analyzer that powers LeakCanary 2. It's a Kotlin standalone heap analysis library that runs at high speed with a low memory footprint.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Making OpenAPI / Swagger Bearable With Your Own DSL

Sebastien Armand — Fri, 02 Aug 2019 19:00:00 GMT

Problem: while OpenAPI is great for describing APIs, generating client SDK code and defining your API contracts, it's definitely not a great experience to write OpenAPI documents from scratch.

Even with the use of references, OpenAPI's mechanism to avoid repetition, a simple document with less than 10 endpoints described ends up at over 1,000 lines for us. To get a feeling for it, this snippet defines a schema that's just a list of intege…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Value in Early Product Analytics

Claire Meyer — Wed, 31 Jul 2019 19:00:00 GMT

Product Analytics is an increasingly common discipline across product teams. Often, teams think a product should mature to a particular size or age before bringing in dedicated analytics or ‘data people’. At Square, Product Analytics is often engage…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s Growth Framework for Engineers and Engineering Managers

Michael White — Tue, 23 Jul 2019 19:00:00 GMT

Since the publication of this post, we have updated our growth framework for engineers and engineering managers. You can learn about our updated growth framework in this [new blog post](https://developer.squareup.com/blog/squares-updated-growth-framework-for-engineers-and-engineering-managers).

At Square, we’re building products and services that help consumers and businesses participate and thrive in the economy. To accomplish this, we need to cultivate an environment where engineers can challenge themselves, achieve their goals for profe…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Effective batching in streaming dataflow jobs

Fasih Awan — Mon, 15 Jul 2019 11:00:00 GMT

Background

Square processes nearly 2 billion payments annually. With payments being processed all over the world at such a fast rate, it becomes difficult to monitor the state of payments. We want to be able to monitor payment traffic in near real time so we c…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Story of an Android Q Leak: attachment crazy town!

P-Y Ricau — Wed, 03 Jul 2019 19:00:00 GMT

Ticket assignment

Our QA team has been testing Square POS on Android Q, and recently assigned the following ticket to me:

We automatically upload memory leaks to Bugsnag in our debug builds, so I took a look. Sure enough, the leaks on Q (Android 10) were off the charts:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Identifying and Scaling a Language Market

Sherry Xia — Fri, 28 Jun 2019 19:00:00 GMT

Background

In 2018, while shadowing Customer Success calls, Square’s internationalization and localization PM noticed that many Square merchants were calling into US Spanish support. Revisiting the product experience in Spanish, she found the user experience t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Spotlight: Robert Harris, CTO at Clutch!

Bobbilee Hartman — Wed, 26 Jun 2019 19:00:00 GMT

In the last few months we’ve been interviewing developers around the world that are using Square APIs. Businesses that vary in size and operate in diverse markets are working with us in many different ways. We’ve learned a lot and have been super in…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square’s New Ruby SDK

Shannon Skipper — Mon, 24 Jun 2019 19:00:00 GMT

We're excited to announce square.rb, our new Ruby SDK gem. You can use square.rb to integrate Square payments into your app. Run your business with Square APIs including Catalog, Customers, Employees, Inventory, Labor, Locations, Orders, and more.

To install the gem, just gem install square.rb from the command line or add gem: 'square.rb' to your Gemfile. Next, all you need to do is provide your access token and you're ready to use Square APIs.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Shipping Binary Frameworks With Swift 5.0

Chris Williams — Fri, 31 May 2019 09:00:00 GMT

"Module Stability"

Swift 5 introduces "ABI Stability", which means the calling conventions between two binaries is now guaranteed to be consistent. Previously, if two binaries were compiled with two different Swift versions, it was not guaranteed that one could call i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

“Everything is an Order”

Tim Hays — Tue, 21 May 2019 09:00:00 GMT

The Orders API is now a one-stop shop for retrieving all of your sales data. Until this point, to build a comprehensive view of your sales, you had to use a combination of the Payments (Connect V1), Transactions, and Orders APIs. We have now updated the Orders API to return all sales, returns, and exchanges regardless of how or when they entered the Square Ecosystem (e.g. Point of Sale, Invoices, Connect APIs, etc). In the process, we added

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Eloquent Labs Joins Square

Alyssa Henry — Tue, 07 May 2019 17:00:00 GMT

Eloquent Labs is a conversational artificial intelligence (AI) services business founded by two leading Natural Language Processing (NLP) researchers. Eloquent specializes in AI approaches to responding to customer questions and feedback, and the te…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

RubyKaigi and the Path to Ruby 3

Shannon Skipper — Mon, 06 May 2019 19:00:00 GMT

Original Image by Mathias Meyer CC BY-SA 2.0

At RubyKaigi in Fukuoka, Japan, Matz spoke at length about Ruby 3—the next major version of the Ruby programming language, scheduled for release on Christmas of 2020. Many of the features planned for Ruby 3 are already well underway and RubyKaigi ha…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

PySurvival Tutorial: Churn Modeling

Stephane Fotso — Fri, 03 May 2019 14:00:00 GMT

This article is the second installment in a four part series, which will include tutorials designed to demonstrate how to easily make the most of the package. You can also find these tutorials on the official website:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Flutter, Android, and Process Death

Brandon Cheng — Fri, 26 Apr 2019 07:00:00 GMT

Back in December 2018, Square launched a shiny new iOS and Android SDK (now 100% Kotlin) called In-App Payments which allows developers to take PCI compliant payments. Since we partnered with Flutter, we also launched with a Flutter plugin on the same day. This sparked joy in my heart because we launched on Android, iOS, and Flutter all at the same time. What made me

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developing on iOS and Android

Jesse Wilson — Mon, 22 Apr 2019 19:00:00 GMT

Over the past 10 years iOS and Android have not only grown and matured, but increasingly converged as well...

Early apps were spartan: a few screens built by a solo developer or a small team. Compare that to today’s apps, which offer surface-layer simplicity but implementation complexity that often goes deep. In these iceberg apps, each user sees what they …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Pricing Subscription Products with a Data-Driven Conscience

David Feng — Mon, 10 Jul 2017 16:58:35 GMT

At Square, Product Analytics is embedded within full-stack product teams, which allows each of us to become a data expert for our respective products. Our high-visibility position(s) within each product allows us to drive the decision-making process…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How we use StackOverflow to support our developers

Tristan Sokol — Tue, 19 Dec 2017 21:17:48 GMT

StackOverflow is an invaluable resource for developers of all skill levels, and is a part of millions of developers’ regular workflow. All of that knowledge is only useful if people are answering questions. We use a combination of tools, design, and…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square In-App Payments SDK for Flutter

Shannon Skipper — Thu, 18 Apr 2019 17:00:00 GMT

Square’s In-App Payments SDK lets developers accept Square-powered payments from within their own mobile apps. With the Flutter plugin for In-App Payments SDK we can take payments in Flutter.

Let’s look at how to take credit card payments in Flutter!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Creating a customer with Ruby

Tristan Sokol — Fri, 06 Oct 2017 20:17:40 GMT

Customer management via API can be incredibly useful when syncing with other systems, automating marketing tasks, and more. If your Customer Directory looks empty and you want to add to it, take a look at the following ruby script:

# load the gem
require 'square_connect'

# setup authorization with a personal access token
SquareConnect.configure do |config|
  config.access_token = 'sq0atp-XXXXXXXXXXXXX'
end

#create a new API instance
api_instance = SquareConnect::CustomersApi…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ruby’s New JIT

Shannon Skipper — Wed, 14 Feb 2018 18:52:06 GMT

CRuby just got a JIT!

There have been many attempts at implementing a JIT for CRuby, the reference implementation of Ruby. None have been merged, until now.

                   ,---.    ,---.     .-./`)  .-./`) ,---------. 
  .     '     ,    |    \  /    |     \ '_ .')\ .-.')\          \ 
    _________      |  ,  \/  ,  |    (_ (_) _)/ `-' \ `--.  ,---' 
   /_\/_ _ \/_\    |  |\_   /|  |      / .  \  `-…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Zooming Out From Engineering

Square Engineering — Thu, 11 Apr 2019 17:24:50 GMT

Originally seen on Greylock Partners’ blog

Leading an organization of 10 employees is considerably different than leading an organization of 10,000+ employees. As teams increase and communication becomes more challenging, a lot can break down. In this episode of Greymatter, we share a fireside discussion from the

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Spin Cycle — Automating the Tedious

Felix Plajer — Tue, 09 Apr 2019 18:16:57 GMT

Spin Cycle makes it easy to automate complex infrastructure tasks. The database team at Square uses it for most of our day-to-day operations — provisioning new clusters and decommissioning old ones, upgrading MySQL and Docker, stopping and starting …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing PySurvival

Stephane Fotso — Fri, 12 Apr 2019 21:06:21 GMT

PySurvival is an open source python package for Survival Analysis modeling.

Today, we’re excited to introduce PySurvival, a python package for Survival Analysis modeling.

This article is the first installment in a four part series, which will include tutorials designed to demonstrate how to easily make the most of the package. You can also find these tutorials on the official website:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Our Connect v2 Labor API

Dina Spitzer — Thu, 04 Apr 2019 21:38:52 GMT

We’re very excited to announce the release of the Square Connect v2 Labor API. Having visibility into daily employee operations and labor costs is a critical part of managing a business. It helps business owners better understand the performance of their business, employees, and ultimately make more informed & cost-effective…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Shard Splits with Consistent Snapshots

Andrés Taylor — Tue, 04 Dec 2018 17:00:00 GMT

Splitting shards into smaller shards

At Square, we have a lot of data being inserted into our databases. To make it possible for MySQL to handle the load, we shard the data using Vitess. Because the amount of data we are receiving is very large and the rate is increasing, we are not do…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Smooth Signatures

Eric Burke — Tue, 27 Jul 2010 07:00:00 GMT

Capturing a signature during a card payment increases security and decreases processing fees. When you pay with Square, instead of signing a receipt with a pen, you sign the screen with your finger:

Tip: Shake the phone to clear the signature.

The signature shows up on the email receipt and helps Square detect and prevent fraud.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Integration Testing Resque with Cucumber

Square Engineering — Mon, 16 Aug 2010 16:00:00 GMT

Written by Zach Brock and Matthew O’Connor.

Square takes integration testing seriously. We use Cucumber and RSpec to test our code during every step of development: on developer pairing machines, continuous integration servers, staging servers and production servers.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Testing Named Scopes

Square Engineering — Thu, 14 Oct 2010 16:00:00 GMT

Written by Zach Brock and Cameron Walters.

Last year Zach wrote a blog post about an easy way to test ActiveRecord’s *named_scope*. It was one of the first snippets he brought with him to the code base here at Square. We’ve been using it extensively ever since. Recently, we made some improvements to the test helper for clarity and ease of use, so we decided it was time to sha…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Fsync or Swim Part 1: Error Handling

Square Engineering — Thu, 17 Mar 2011 16:00:00 GMT

Written by Bob Lee.

Welcome to part one of our series on file-based persistence. We’ll talk a lot about Android, but these lessons translate easily to any POSIX-compliant platform.

Writing files correctly is notoriously difficult, on par with programming concurrent data structures. In both cases, one must consider data visibility, [re]ordering of operations, and optimizations in the underlying platform. Just like virtual machi…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

PostgreSQL: Data is Important

Square Engineering — Mon, 06 Jun 2011 16:00:00 GMT

Written by Mike Lewis.

At our engineering all-hands meeting, I presented a 5-minute lightning talk on the merits of PostgreSQL. In the spirit of being able to search for data, I converted the deck into the following blog post. Enjoy!

PostgreSQL: Data is Important

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

BorderPatrol: KML border checking in Ruby

Square Engineering — Tue, 05 Jul 2011 16:00:00 GMT

Written by Zach Brock.

BorderPatrol allows you to easily check if a point exists within a region defined by a KML file. Thanks to Google Map’s KML export and shape drawing, this makes it really easy to define regions of interest and quickly check if points are inside of them. BorderP…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Yes, Redis cares about your load balancing strategy

Square Engineering — Wed, 06 Jul 2011 16:00:00 GMT

Written by Chris Chandler.

The funny thing about distributed faults is that they’re largely created by several autonomous systems doing exactly what they’re supposed to do. More often than not the problem is that what they’re normally supposed to do doesn’t translate into how…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

iOS Integration Testing

Square Engineering — Thu, 14 Jul 2011 16:00:00 GMT

Written by Eric Firestone.

We love iOS for the fast and versatile experience it offers. But what we think is really cool is that it brings these attributes to the development process as well. The App Store makes short release cycles easy, allowing developers to address feedba…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Cube: Time Series Visualization

Square Engineering — Thu, 15 Sep 2011 16:00:00 GMT

Written by Mike Bostock.

We’ve found visualization to be a powerful tool with myriad applications at Square, whether it’s monitoring system performance, analyzing website traffic, helping merchants optimize their business, or finding new ways to combat fraud. So we’re const…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Codenames

Square Engineering — Thu, 29 Sep 2011 16:00:00 GMT

Written by Zach Margolis.

A lot of engineering projects get codenames. Numbered revisions can sometimes get confusing, and besides, themed names are way cooler anyways. We don’t spend too much time on coming up with codenames, but it’s one of my favorite parts of being a Sof…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Sass Why for the CSS Guy

Square Engineering — Fri, 30 Sep 2011 16:00:00 GMT

Written by Beau Smith.

An intro to Sass and Compass for CSS fans.

After you start using Sass and Compass you will never want to write plain CSS ever again. These tools have saved countless hours of development time at Square. This 40-minute video intro (+ slides) should give you a solid overview of how Sass and Compass can change the way you style you…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Why We Pair Interview

Square Engineering — Wed, 05 Oct 2011 16:00:00 GMT

Written by Allen Cheung.

This May Sound Familiar

“Write substr() for me in order n time.”

If you’ve ever tried to get a job as a software engineer, you’ve undoubtedly come across the dreaded whiteboard interview: implement this function, and do it efficiently with a clever algorithm. Bonus points for esoteric data structures.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

iOS Integration Testing, Part 2

Square Engineering — Fri, 04 Nov 2011 16:00:00 GMT

Written by Jim Puls.

A few months ago, we released KIF, our integration testing framework for iOS. We’ve heard from dozens of teams and companies using KIF to keep their apps functional, and we have over 600 followers and 50 forks on GitHub. The response has been astounding.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Coding Challenge: The Luhny Bin

Square Engineering — Mon, 14 Nov 2011 17:00:00 GMT

Written by Bob Lee.

“To err is human; to forgive, divine.” -Alexander Pope

Mistakes happen. At Square, we accept that human error is inevitable. We anticipate potential slip-ups and implement safety measures to mitigate — and oftentimes completely eliminate — any repercussions.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing SocketRocket: A WebSocket library for Objective-C

Square Engineering — Tue, 07 Feb 2012 17:00:00 GMT

Written by Mike Lewis.

The WebSocket Protocol is a network protocol designed for the web to enable browsers to have bi-directional communication with a server.

WebSockets are also useful in native mobile applications. By using WebSockets, you can reuse existing tools built for the web, just like how most mobile apps reuse HTTP for their APIs.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Cane: failing your build for code quality problems

Square Engineering — Mon, 13 Feb 2012 17:00:00 GMT

Written by Xavier Shay.

Code review and pairing are great techniques to keep code quality high, but they are expensive. Automated tools are not.

The cheapest method for detecting certain classes of problem — method complexity, whitespace issues, missing documentation, missing code coverage — is automation. No one should be distracted by these problems by the time the code gets to review.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ember and D3: Building responsive analytics

Square Engineering — Wed, 04 Apr 2012 16:01:00 GMT

Written by Allen Cheung.

A few months back, as we sat down to think about how Square was going to transform the over-the-counter experience with Register 1.0, we also realized that we wanted to augment our users’ understanding of their own businesses with more analytics. We…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Monitoring Resque with Graphite

Square Engineering — Mon, 14 May 2012 16:01:00 GMT

Written by Mike Bostock.

Square uses Resque to manage scheduling and execution of background jobs. We run millions of jobs every day in prioritized queues, distributing jobs across banks of machines. Resque has a lovely built-in dashboard that shows you the current state of the system: how m…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using ActionBarSherlock As A Base

Square Engineering — Tue, 15 May 2012 16:01:00 GMT

Written by Jake Wharton.

ActionBarSherlock is an open source Android library which aims to bring the full experience of the action bar design pattern to previous versions of the platform under a unified API and theme. The library delegates to the built-in platform action bar where appropriate and uses a compatibility implementation otherwise.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

5 Questions with Eric Burke

Square Engineering — Fri, 01 Jun 2012 16:01:00 GMT

Written by Katie.

To kick off our new Corner series “5 Questions With…” I sat down with Android Developer Eric Burke to learn more about what gets him out of bed every morning.

What brought you to Square?

About ten years ago I was working at a St. Louis based consulting company. As luck would have it, I interviewed Bob Lee. As he likes to tell it, I was a terrible interviewer, asking obscure questions about the Servlets and the WEB-INF directory. Bob…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

fdoc: an API Documentation Tool

Square Engineering — Tue, 19 Jun 2012 16:01:00 GMT

Written by Zach Margolis.

**fdoc** is a tool we’ve built to help us maintain our API documentation. It provides a schema for our endpoints and a central place for documentation. We’re really excited to open source fdoc today.

We use fdoc for two things:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Decoupling Android App Communication with Otto

Square Engineering — Mon, 02 Jul 2012 16:01:00 GMT

Written by Jake Wharton.

Otto is a tiny but useful library for Android which aims to simplify how parts of your application communicate with each other.

The Situation

As Android applications increase in complexity, ensuring effective communication between different parts becomes more and more difficult.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Welcome Atlanta Squares

Square Engineering — Fri, 20 Jul 2012 16:01:00 GMT

Written by Bob Lee.

This week, as part of our largest class of new hires ever, we welcomed to Square a group of talented engineers who will be based in Atlanta. Their experience with various developer tools – like Google Web Toolkit, Google App Engine, Collide, and Dar…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Smoother Signatures

Square Engineering — Fri, 20 Jul 2012 16:01:00 GMT

Written by Rob Dickerson.

In a previous post, we described how Square makes signatures appear smooth on Android devices. In the latest release of Square Card Reader, we’ve made signing on Android devices even smoother, more beautiful, and more responsive. The three major changes are an improv…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

4 Questions with Madelin Woords

Square Engineering — Mon, 23 Jul 2012 16:01:00 GMT

Written by Katie.

We know you love the technical details of how we run things at Square, but we thought you might also love to meet the amazing people behind it. Meet Madelin!

What were you doing before Square?

Before Square, I was a designer at a local development agency, and previously worked as a web developer at Make Magazine. It’s an interesting and tough transition between design and code, but has ultimately shaped the way I approach problem solving.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Chasing a Cunning Android bug

Square Engineering — Mon, 06 Aug 2012 16:01:00 GMT

Written by Jesse Wilson.

Most software bugs are small, pesky problems with an obvious cause and a simple solution. But every once in a while I encounter a bug who is more advanced: a bug that hides in the shadows of other bugs, avoiding detection by its coffee-drinking pred…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Pump: A Faster Way To Write Cascading Flows

Square Engineering — Mon, 27 Aug 2012 16:01:00 GMT

Written by Bryan Duxbury.

One of the tools that Square uses for “big data” analysis is Cascading. There are plenty of competitors in the same space (1, 2, 3), but we particularly like Cascading because of its language model and its extensibility.

However, one of the things we don’t like about Cascading is how much code it can take to write even simple Flows. This is an understandable consequence of being a DSL hosted in Java, but it can be a real drag on productivity, particularly when tryin…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

PonyDebugger: Remote Debugging Tools for Native iOS Apps

Square Engineering — Thu, 30 Aug 2012 16:01:00 GMT

Written by Wen-Hao Lue and Mike Lewis.

Web developers have amazing debugging tools right now with Chrome Developer Tools, WebKit Inspector, and FireBug. The iOS team at Square thought, “Why can’t iOS developers use this toolset for native applications?”

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Intern Profile — Kingston Tam

Square Engineering — Thu, 11 Oct 2012 16:01:00 GMT

Written by Kingston Tam.

This summer our engineering team was fortunate enough to be joined by fantastic, exuberant talent from schools across the country. From this year’s amazing crop of summer interns, we’d like you to meet Stanford senior Kingston Tam.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Mockito on Android

Square Engineering — Mon, 22 Oct 2012 16:01:00 GMT

Written by Jesse Wilson.

At Square we love unit tests. Our comprehensive test suite helps us to develop Android apps with confidence.

But without proper tools many scenarios are cumbersome to unit test. For example, suppose we want to pump up the device’s volume in Square Wallet. We have a method that cranks the ringer up to eleven unless the phone is silent:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Squash: The open-source exception notification tool

Square Engineering — Wed, 16 Jan 2013 17:01:00 GMT

Written by Tim Morgan.

Squash is a web app and collection of client libraries that records exceptions in your code, and gives you the tools you need to analyze and fix the bugs that caused those exceptions. The main emphasis is finding someone who can take responsibility …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Transparency with JPEGs

Square Engineering — Fri, 18 Jan 2013 17:01:00 GMT

Written by Christian Williams and Kiran Ryali.

We have some of the best — and most demanding — designers in the world at Square.

While pushing the bounds of design, we tend to push the bounds of the platform. For the new version of Wallet, our designers asked for a landing page with high resolution transparent images. These images would animate over each other creating a real…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

TimesSquare: a calendar view for iOS and Android apps

Square Engineering — Thu, 31 Jan 2013 17:02:00 GMT

Written by Jim Puls and Eric D.

Have you sent a gift card with Square Wallet yet? You can treat all of your friends to their favorite neighborhood spot — no matter where you are — instantly from your phone.

And if you’re one to leave gift-giving to the last minute, Square has you covered. Your sweetheart will never be disappointed when you pre-select the day you want the gift card delivered.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

ES6 Module Transpiler — Tomorrow’s JavaScript module syntax today

Square Engineering — Fri, 15 Feb 2013 17:02:00 GMT

Written by Brian Donovan.

Modern JavaScript has a number of different ways to modularize your code. Each approach has its own advantages and disadvantages, but none of them strike the right balance. At Square we have a number of different web applications using a variety of …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Hacking Up the Odominator

Square Engineering — Wed, 06 Mar 2013 17:02:00 GMT

Written by Bryan Duxbury.

Like most Squares, I like to make things. By day, that means coding up a storm, but by night, you can often find me standing over a laser cutter or inhaling some solder fumes. When our quarterly Hack Week rolls around, I like to try to think of proj…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Mapping Square Payments During the Super Bowl

Square Engineering — Mon, 11 Mar 2013 16:02:00 GMT

Written by Tom Carden.

Data visualization touches many aspects of Square’s business, from the interactive reports on our merchant dashboards to our internal metrics and monitoring tools. In addition to these activities we look for occasional opportunities to visualize the activity around an event or promotion.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Driving Analysis by Managing Data with ETL (a Ruby gem!)

Square Engineering — Thu, 14 Mar 2013 16:02:00 GMT

Written by Jeff Iacono.

Business Intelligence at Square

At Square there are two main teams who ensure that data is accessible and accurate for analysis across the company. The Data Engineering team takes data from disparate sources and feeds it into databases that are accessible to analysts. The Business…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square’s Open Source Portal

Square Engineering — Mon, 18 Mar 2013 16:02:00 GMT

Written by Jake Wharton.

I am happy to announce that a listing of all the open source projects from Square can now be found at **square.github.com**!

As a company, Square relies on numerous projects run by the open source community to function. In an effort to contribute back to the community we have open sourced many projects developed internally. Before today the only way to discover these proj…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Java Puzzle: Square Root

Square Engineering — Tue, 19 Mar 2013 16:02:00 GMT

Written by Wouter Coekaerts.

There are several algorithms to calculate a square root. But to solve this puzzle, you’ll need a different approach.

Can you find the square root of a huge number, without even looking at it?

package square**;**

import java.math.BigInteger;
import java.security.SecureRandom;

public class SquareRoot {
  public static final int BITS = 10000;

  private static BigInteger n =
    new BigInteger(BITS, new SecureRandom()).pow(2);

  public s…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Making TimesSquare fast on iOS

Square Engineering — Wed, 20 Mar 2013 16:02:00 GMT

Written by Jim Puls.

A couple of months ago, we told you about TimesSquare, an open-source library for displaying calendars on iOS and Android that’s fast and flexible.

Making it flexible was easy enough: use the system calendar APIs to do all of your calculations, put each week into a table row, call it a day. Everybody is pretty good at coming up with custom table rows.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Java Puzzle: Square Root — Solution

Square Engineering — Mon, 25 Mar 2013 16:02:00 GMT

Written by Wouter Coekaerts.

Here’s the solution to our square root puzzle.

Sherlock

Take another look at that code, and use your imagination. Imagine that you are the SquareRoot class. You have a square number written on a secret piece of paper in your pocket. Sherlock is interrogating you to figure out its square root. Whenever he makes a guess, you divide your number by that guess (integer division), and i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Resurrection of Testing for Android

Square Engineering — Wed, 03 Apr 2013 16:02:00 GMT

Written by Jake Wharton.

When testing Android applications, documentation and tools can be sparse. At Square, verifying the behavior of our applications is an essential part of our day-to-day development — and to make testing easier, we have created and refined a set of too…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Run All Projects Like Open Source Projects

Square Engineering — Tue, 09 Apr 2013 16:02:00 GMT

Written by Xavier Shay.

I run all of my internal company projects the same way I run my open source projects.

Fundamentally this means focusing on stewardship, not ownership. Push feature requests back on to those requesting them. Don’t feel compelled to implement everything everyone asks of you. Fix the most critical bugs, but others should feel encouraged…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Inside a Square Inforad

Square Engineering — Wed, 24 Apr 2013 16:02:00 GMT

Written by Sean Lazar.

At Square, we have inforads (information radiators) hanging all over the office. They display everything from up-to-the-minute metrics about our business, to software build and infrastructure statuses, and even the day’s lunch menu. Other inforads d…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

What’s It Like To Work At A Startup

Square Engineering — Thu, 02 May 2013 16:02:00 GMT

Written by Zach Brock.

Square’s own Engineering Manager Zach Brock recently participated in a live webcast entitled Startup Life. The webcast was organized by Readyforce, who helps connect students with startups. Zach spent an hour answering questions from students about …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Seven Days of Open Source

Square Engineering — Mon, 06 May 2013 16:02:00 GMT

Written by Jake Wharton.

Square Engineering is celebrating the arrival of Google’s annual I/O conference here in San Francisco by releasing seven open source projects, all of which are major milestones for us.

Two of the major development platforms in focus at I/O are Android and Java. At Square, we are deeply invested in both of these platforms. As such, all of the releases over the next seven weekdays will be focused on one or both of these great techno…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing OkHttp

Square Engineering — Mon, 06 May 2013 16:02:00 GMT

Written by Jesse Wilson.

Android has two HTTP clients built-in:

Apache HTTP Client is stable yet basic.
HttpURLConnection supports advanced features, but suffers a few annoying bugs on older devices.

At Square, we want it all: advanced features that work right on every device. We also want to ship new tech without waiting for new Android releases.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Slash Your Wiring Code With Dagger

Square Engineering — Tue, 07 May 2013 16:02:00 GMT

Written by Jesse Wilson.

I hate the wiring code that creeps in as my app grows. The SyncService needs an HttpClient and the AccountProfile needs a PhotoPicker. In each case I need either a difficult-to-test direct dependency, or to write a clumsy Factory thingy:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

MimeCraft, JavaWriter, and ProtoParser

Square Engineering — Wed, 08 May 2013 16:03:00 GMT

Written by Jake Wharton.

In any complex project you’ll need a variety of tools to solve a variety of problems. The general rule that we use when developing libraries is “perform one task and perform it well”. Here are three purpose-built libraries which do just that:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Better Android Testing with Robolectric 2.0

Square Engineering — Thu, 09 May 2013 16:03:00 GMT

Written by Christian Williams and Jake Wharton.

As we have mentioned before on this blog, verifying the behavior of our applications is an essential part of our day-to-day development. Robolectric is a framework which facilitates writing unit tests for your Android code, which we use extensively at Square. Today we are happy to announc…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Boost Your Productivity with IntelliJ Plugins

Square Engineering — Fri, 10 May 2013 16:03:00 GMT

Written by Kiran Ryali.

As developers, we rely on our tools to keep us productive and focused. The better our tools, the more productive we can be. Today, we are releasing IntelliJ plugins designed to complement two of our popular open source libraries, Dagger and Otto.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square at Google I/O Developer Sandbox

Square Engineering — Mon, 13 May 2013 16:03:00 GMT

Written by Jake Wharton.

If you are attending Google I/O this year then be sure to stop by Square’s booth in the Developer Sandbox! Engineers will be on-hand to show demos and answer questions about our open source tools and libraries.

Google I/O is an annual developer conference featuring highly technical, in-depth sessions, and showcasing the latest from Google’s product teams and partners. Google I/O returns to San Francisco’s Moscone West Convention Center from May 15–17, 2013.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Easy HTTP Requests with Retrofit

Square Engineering — Mon, 13 May 2013 16:03:00 GMT

Written by Jake Wharton.

There are few fundamentals to application development. One that is almost always guaranteed is making HTTP requests and reading their responses. Retrofit is an open source library from Square which simplifies HTTP communication by turning remote API…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Enhance Your Application Using Picasso

Square Engineering — Tue, 14 May 2013 16:03:00 GMT

Written by D. Koutsogiorgas and Jake Wharton.

Today, we would like to introduce and open source Picasso, our solution for image downloading and caching on Android.

Picasso aims to be fast and simple to use — often requiring only one line of code.

Picasso**.**with**(**context**).**load**(**"http://example.com/logo.png"**).**into**(**imageView**);**

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Replacing Google Authenticator with Yubikey on OS X

Square Engineering — Tue, 28 May 2013 16:03:00 GMT

Written by Xavier Shay.

After two consecutive days leaving my phone at home, it started to hit home just how hard it was to do my job on the Production Engineering team without being able to access our datacenters. We require two-factor authentication for SSH, using a TOTP with the freely available

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

JRuby at Square

Square Engineering — Tue, 25 Jun 2013 16:03:00 GMT

*Written by *Matt Wilson.

Recently we internally launched Minecart, a project that deeply ties Ruby applications into our Java service infrastructure. To accomplish this we had to dive into the bowels of JRuby. My hope is to share many of our learnings along with a couple of…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Guice for the Rubyist

Square Engineering — Wed, 26 Jun 2013 16:03:00 GMT

Written by Matthew Todd and Matt Wilson.

Square heavily utilizes Guice in its Java codebase. Rather than fully wire Ruby into the dependency graph, we’ve built a small API to simulate field injection onto our Ruby objects. This allows our developers to write native-feeling Ruby code while still providing access to the…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using Java Protocol Buffers in JRuby

Square Engineering — Thu, 27 Jun 2013 07:00:00 GMT

Written by Daniel Neighman and Matt Wilson.

At Square, we use Protocol Buffers for communication between services. Ruby has good native Protocol Buffer support, but by using the compiled Java classes, we can leverage all the benefits of any extensions and infrastructure relying on those extensions. We’ll demonstrate how we utilize Java-backed Protocol Buffers while still enjoying idiomatic Ruby for Protoc…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Ruby Sequel ORM on the Hibernate Connection Pool

Square Engineering — Fri, 28 Jun 2013 16:03:00 GMT

Written by Daniel Neighman and Matt Wilson.

Square’s Java services use either Hibernate or Jooq as their ORM. As with the theme of the series, we have some pretty cool infrastructure which instruments and enforces proper use of database connections. In this post we will show how to put the Ruby ORM,

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Maven, Gems, and a JRuby Console for All

Square Engineering — Tue, 02 Jul 2013 16:03:00 GMT

Written by Matt Wilson.

How great would it be if your Java and Ruby applications had access to equivalent consoles? At Square, we use shaded jars to distribute and run applications. A shaded jar contains all the necessary dependencies and allows any app to be started simply via java -jar path-to-jar.jar. We have also been able to bundle our JRuby integration framework (Minecart) into these s…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Rack Servlet

Square Engineering — Thu, 11 Jul 2013 16:03:00 GMT

Written by Matthew Todd.

Today we’re releasing Rack Servlet, a small JRuby-backed servlet designed for embedding in your Java application.

Rack Servlet comes from our ongoing Minecart work to bring Ruby applications into Square’s sophisticated Java service container.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Reversing Bits in C

Square Engineering — Thu, 01 Aug 2013 16:03:00 GMT

Written by Charles Nicholson.

Thanks to readers rjs, meteorfox in the comments, and reader lnxturtle over on the Reddit thread (!) for correcting my poor choice of words. I incorrectly used the phrase Cache Coherence when the correct phrase was (Spatial / Temporal) Cache Locality. Your attention to detail is appreciated!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Small Grunts

Square Engineering — Tue, 06 Aug 2013 16:03:00 GMT

Written by Eric Strathmeyer.

At Square, we encourage people to not limit their ideas to things they already know how to do. There are plenty of opportunities for people to expand their skills, like programming classes for engineers and non-engineers. Here’s a post I shared on m…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Responsive Images with Apropos

Square Engineering — Wed, 21 Aug 2013 16:03:00 GMT

Written by Gabriel Gilder.

有志による日本語訳はこちらから。

When Square’s front-end engineering team was building our Japanese website, we decided early on that we needed to support a wide variety of devices, and that responsive design was the right way to do that. (Who wants to support a completely separate “mobile site”?) However, we weren’t sure how we would serve every visitor…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Bluetooth Printing Support for iPad

Square Engineering — Thu, 22 Aug 2013 16:04:00 GMT

Written by Grant Kennell.

Intro

I’m a software engineering intern at Square and have been working on Bluetooth printer support for iPad. This feature was released in our latest Square Register build and brings physical receipt printing using Star printers to a mobile customer base…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Wire Protocol Buffers

Square Engineering — Fri, 23 Aug 2013 16:04:00 GMT

Written by Dan Rice.

What is Wire?

Wire is a new, open-source implementation of Google’s Protocol Buffers. It’s meant for Android devices but can be used on anything that runs Java language code.

At Square, we use Protocol Buffers extensively. Protocol Buffers are a language- and platform-neutral schema for describing and transmitting data. Developers can use the same schemas across diverse environments, including the environments we care ab…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

LGTM: A Validation Library for JavaScript

Square Engineering — Mon, 26 Aug 2013 16:04:00 GMT

Written by Brian Donovan.

Validating user input and displaying error messages is a core part of nearly any application, especially when that application is a web page. There are many existing solutions to this problem, but too often they make assumptions that don’t work for …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Fly Vim, First-Class

Square Engineering — Wed, 28 Aug 2013 16:04:00 GMT

Written by Riley Strong.

Engineers at Square use a wide variety of code editors: Sublime, IntelliJ, Xcode, and Vim are among the most popular. Over time, the Square Vim enthusiasts have compiled settings, shortcuts, and plugins into a single repo we lovingly call Maximum Awesome

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s Code Camp for High School and College Women Engineering Students

Square Engineering — Wed, 04 Sep 2013 16:04:00 GMT

Written by Kat Hawthorne.

Last year I participated in Square’s inaugural College Code Camp, a four-day immersion program for women engineering students from all over the United States and Canada. The program was built around four (we like the number four a lot at Square) foundational goals: leadership, community, engineering ability, and…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Kochiku: CI for long test suites

Square Engineering — Fri, 06 Sep 2013 16:04:00 GMT

Written by Rob Olson.

Back in the summer of 2011, every request to Square’s servers went through a single monolithic Rails application we lovingly call SquareWeb. At the time, SquareWeb had hundreds of models and controllers, all with tests to cover their behavior. In ad…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Pair Programming Interviews

Square Engineering — Wed, 11 Sep 2013 07:00:00 GMT

Written by Parth Upadhyay.

About Me

My name is Parth Upadhyay and I’m a rising senior at the University of Texas at Austin, majoring in Computer Science. This summer, I interned at Square on the Register team.

Interviewing At Square

When I first started exploring internship opportunities at Square, I didn’t know a lot about the engineering culture at Square — that is until I came in for pair programming interviews. Previously I had only experienced a more standard interview pro…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The @Square Tweetwriter

Square Engineering — Thu, 26 Sep 2013 16:04:00 GMT

Written by Scott Perry.

Each quarter, Square sets aside a full week for everyone in the company to build something they believe should exist in the world and transform ideas into working prototypes. Hack Week is an opportunity to create and innovate in the exact same way S…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s Open Approach to Code

Square Engineering — Tue, 01 Oct 2013 16:04:00 GMT

Written by Lindsay Wiese.

Nearly 3 years ago we open sourced our first project at Square: Retrofit. Since then we’ve released more than a quarter of a million lines of code in more than 60 open source projects — a project, on average, every 2.5 weeks.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How to win at career fairs

Square Engineering — Mon, 07 Oct 2013 16:04:00 GMT

Written by Jim Puls.

College students! Especially those of you in the programming-type vocations!

It’s recruiting season again — and by “recruiting season” I mean “the school year.” If you’re smart, you’re looking for work, either for next summer or for when you graduate. (Funny story: when I was in college, my advisor famously addressed a room …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Hardware at Square

Square Engineering — Wed, 09 Oct 2013 16:04:00 GMT

Written by Lindsay Wiese.

At Square, we are developing hardware in an industry that has seen very little innovation in more than 50 years.

Our first Square Reader was soldered together in our original office, Jack Dorsey’s apartment. Five years and three major iterations of Square Reader later, we continue to lead all electrical, mechanical, and firmware design and engineering in-house…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Parliament: A Threshold Secret Sharing Service

Square Engineering — Wed, 23 Oct 2013 16:04:00 GMT

Written by Tobias Lauinger.

High-value secrets need proper protection. A well-established scheme to achieve this is secret sharing, which splits a secret into many parts and reveals nothing about the secret unless a quorum of shares is provided. This technique is used during key ceremonies

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A journey on the Android Main Thread — PSVM

P-Y Ricau — Wed, 30 Oct 2013 16:04:00 GMT

Written by Pierre-Yves Ricau.

There is an article on coding horror about why we should learn to read the source. One of the great aspects of Android is its open source nature.

When facing bugs that were related to how we interact with the main thread, I decided to get a closer look at what the main thread really is. This article describes the first part of my journey.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Culture Fit

Square Engineering — Thu, 21 Nov 2013 17:04:00 GMT

Written by Jack Danger.

At Square we talk a lot about our “hiring bar.” If you’ve ever interviewed here you know that we put a lot of work into each interview. You’ll have a recruiting coordinator ensuring the schedule for your interview day (yes, it’s a full day) is clear and reasonable, and your interviews stay on-time. At the beginning of the day you’ll have time to talk to…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Viewfinder Joins Square

Square Engineering — Tue, 03 Dec 2013 17:05:00 GMT

Written by Bob Lee.

We are excited to announce that the Viewfinder team is joining Square. The team is incredibly talented, having built an app that blends beautiful design and highly technical engineering to create personal, human experiences. This too is our mantra at Square, and the Viewfinder team’s expertise …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Pair Programming Interviews, Part II

Square Engineering — Wed, 04 Dec 2013 17:05:00 GMT

Written by Ed Ruder.

You may have heard that Square conducts several pair programming interviews when evaluating full-time and intern software engineers. You may also kinda-sorta know what pair programming is, but maybe you’ve never done it before. Or maybe you have but you’re not sure i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Securing RubyGems with TUF, Part 1

Square Engineering — Fri, 06 Dec 2013 17:05:00 GMT

Written by Xavier Shay.

Over the last week, a small team¹ here at Square has been working on integrating The Update Framework (TUF) with RubyGems to help protect the community from compromises like the one that happened earlier this year.

In this series of blog posts, I aim to explain the fundamental concepts of TUF and how they apply to RubyGems. This is not a rigourous explanation or justification of the security properties of TUF (refer to the specification for that). Instead, it …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Securing RubyGems with TUF, Part 2

Square Engineering — Mon, 09 Dec 2013 17:05:00 GMT

Written by Xavier Shay.

This is the second part of the Securing RubyGems with TUF series. Start with part 1 if you haven’t read it yet.

In the last post, we covered how The Update Framework (TUF) protects clients from installing maliciously modified gems. In this post, we extend that system to allow developers to update their own gems. As a refresher, our current setup looks like this:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Securing RubyGems with TUF, Part 3

Square Engineering — Tue, 10 Dec 2013 17:05:00 GMT

Written by Xavier Shay.

This is the third and final part of the Securing RubyGems with TUF series. Start with part 1 and part 2 if you haven’t read it yet.

In the last post, we covered how The Update Framework (TUF) enables developers to securely sign for their code, protecting clients from installing maliciously modified gems. In this post we cover a grab bag of other features provided by TUF. It defends against many more attacks than I would have thoug…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Evenly Joins Square

Square Engineering — Wed, 11 Dec 2013 17:05:00 GMT

Written by Gokul Rajaram.

At Square, we are committed to creating a better experience for our merchants by helping them focus on their customers, rather than on the payment itself. From paying with your name with Square Wallet, to designing Square Stand for conversational or…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Let it snow!

Square Engineering — Thu, 19 Dec 2013 17:05:00 GMT

Written by Bob Lee.

If you sent or received Square Cash recently, you might have noticed slight precipitation backdropping our email headers. It all started last week when we decided to do something special for the holidays. I reckon my teammates thought I was joking when I shouted out with glee, “falli…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A journey on the Android Main Thread — Lifecycle bits

P-Y Ricau — Thu, 26 Dec 2013 17:05:00 GMT

Written by Pierre-Yves Ricau.

In the previous part we took a dive into loopers and handlers and how they relate to the Android main thread.

Today, we will take a closer look at how the main thread interacts with the Android components lifecycle.

Activities love orientation changes

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Capture The Flag

Square Engineering — Fri, 17 Jan 2014 17:05:00 GMT

Written by Sam Quigley.

I’m very happy to announce the launch of the Matasano/Square Capture the Flag Challenge.

The challenge is based around finding vulnerabilities in some firmware running on an MSP430 chip. The CTF gives you a debugging interface to the system, and each level has a new vulnerability that you’ll have to find and exploit in order to get to the next stage. You’ll learn assembly, overflow buffers, and crack DRM as you advance throug…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Dynamic Images with Thumbor

Square Engineering — Mon, 20 Jan 2014 17:05:00 GMT

Written by Jake Wharton.

Square uses a lot of user-generated images which are displayed on many mediums. An image for a single item can appear in the Dashboard, on a Market page, in the Register client (on an iPad, iPhone, or Android), in an email receipt, or in Wallet (on iPhone or Android). In order to do this in an efficient, consistent, and cross-platform way we leverage an application named Thumbor.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square From the Trenches, Month One

Square Engineering — Tue, 21 Jan 2014 17:05:00 GMT

Written by Peter Mattis.

I joined Square’s New York engineering team a little over a month ago. Prior to joining Square, I had been aware of the company and was impressed by their products, but had no clear picture of the culture and the inner workings of teams. This post i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Android String Formatting with Phrase

Square Engineering — Wed, 22 Jan 2014 17:05:00 GMT

Written by Eric Burke.

Phrase is a micro-library for text token replacement on Android. Phrase solves a few simple problems we noticed after translating Square Register to French and Japanese.

Suppose strings.xml contains this string definition.

<string name="greeting">
  Hello %1$s, today\'s cook yielded %2$d %3$s.
</string>

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Simpler Android apps with Flow and Mortar

Square Engineering — Thu, 23 Jan 2014 17:05:00 GMT

Written by Ray Ryan.

Doctor, it hurts when I go like that. Don’t go like that! —Henny Youngman

When Fragments were introduced to Android the Square Register team jumped on board. We were already chopping activities into subscreens in a clumsy way, and we did ourselves a lot of good moving to the new hotness. But we also bought ourselves a lot…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Meet Jake

Square Engineering — Fri, 24 Jan 2014 17:05:00 GMT

Written by Lindsay Wiese.

While Jake Wharton cannot divulge what he is currently working on at Square — it’s a “top-secret new project” — he did agree to answer a few questions.

What are you currently working on?

I am currently working on the Android client for a brand new product. Previously, I worked on the Android clients for Square Wallet, Square Register, and to a much lesser degree, Square Cash.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Campfire Camaraderie

Square Engineering — Tue, 28 Jan 2014 17:05:00 GMT

Written by Shana Hu.

*College Code Camp is our four-day immersion program for women studying computer science. Berkeley student Shana Hu shares her experience.*

Last week, I went camping for the first time. There were no tents or sleeping bags, but there was a fire on the first night. And in its dim glow, 21 women from colleges across the U.S. and Canada milled about a chilly backyard in San Francisco, slow…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

An announcement of almost incalculable value

Square Engineering — Fri, 31 Jan 2014 17:05:00 GMT

Written by Zach Brock.

It has come to our attention that certain other companies are running around making misguided claims as to the primacy of certain dinosaurs. We wish to set the record straight.

The Shuvosaurus is the greatest dinosaur of all time. Bar none, without exception and basically by definition. Consider that all other dinosaurs were painstakingly unearthed, grain of dirt by grain of dirt. Armies of khaki safari vested graduate students spent tho…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Faster RSA in Java with GMP

Square Engineering — Fri, 14 Feb 2014 17:06:00 GMT

Written by Scott Blum.

At Square, we care a lot about seller experience, and part of that is making sure our services run as fast as possible. One service I’ve had the chance to help build is our seller session service. The session service essentially does two things:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Eliminating stringly-typed code in Objective-C

Square Engineering — Wed, 19 Feb 2014 17:06:00 GMT

Written by Jim Puls.

As iOS developers, we can use any development environment we want, as long as it’s Xcode. Beyond the Objective-C language, Xcode gives us a bunch of really awesome features for app development, including storyboards and asset catalogs. But all of the great convenience comes with some potential headaches.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

BookFresh joins Square

Square Engineering — Wed, 26 Feb 2014 17:06:00 GMT

Written by Gokul Rajaram.

Sellers use Square for far more than accepting payments: They manage their point of sale with Square Register, run loyalty programs and promotions for customers, and access important analytics that help them make better business decisions. Sellers o…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Market Accepts Bitcoin

Square Engineering — Mon, 31 Mar 2014 16:06:00 GMT

Written by Ajit Varma.

Sellers should never miss a sale. We’re building tools so sellers can accept any form of payment their customers want to use. Making commerce easy means creating easy ways to exchange value for everything from a massage to a DODOcase for your iPad.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Cash introduces Activity View

Square Engineering — Tue, 08 Apr 2014 16:06:00 GMT

Written by Brian Grassadonia.

At Square we view commerce as a form of communication — a way for individuals to exchange value with one another, whether it be goods, services, ideas or experiences.

When we built Square Cash, we had this idea of conversation in mind. Our goal was to make it as easy to send money as it is to send an e-mail. We want everyone — no matter where they are or what devices they use to be able to exchange value with their friends and family eff…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Buffering data with Okio

Square Engineering — Wed, 09 Apr 2014 16:06:00 GMT

Written by Jesse Wilson.

One of the most challenging projects I’ve worked on is OkHttp, Square’s HTTP client for Java. It offers interesting problems for API design (how does the application configure caching?), performance (how long should we hold idle connections?) and code structure (how eagerly do we parse headers?). These decisi…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Square Deal for Women

Square Engineering — Wed, 30 Apr 2014 16:06:00 GMT

Written by Tali Marcus.

College Code Camp is our four-day immersion program for women studying computer science. We’ve been so inspired by what we’ve seen these young women accomplish that we decided to host our second College Code Camp of the year.

We are now accepting applications for College Code Camp, which takes place August 13–16. Wellesley student Tali Marcus shares her experience participating in Code Camp and being a women in STEM.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Open Sourcing Viewfinder

Square Engineering — Mon, 05 May 2014 16:06:00 GMT

Written by Peter Mattis.

Five months ago, our small team at Viewfinder joined Square. We were inspired by Square’s mission and eager to join a world-class engineering and design team, but we were also excited by the company’s commitment to open source.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Connection goes down, business stays up

Square Engineering — Tue, 06 May 2014 16:06:00 GMT

Written by Michael White.

Like a great employee or business partner, sellers should always be able to count on Square. And there’s nothing more important than being able to accept a payment, no matter where you’re selling. That’s why last week we introduced Offline Mode for …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Comparison of Go Web Frameworks

Square Engineering — Thu, 22 May 2014 16:06:00 GMT

Written by Peter Mattis and Jack Danger.

A few months ago we introduced Go to our system at Square and it’s quickly become one of our sharpest tools. We recently evaluated Go web frameworks looking for one that fits us best.

TL;DR: We recommend just using the net/http package in the standard library to start. And if you want help with request routing we recommend looking at Gorilla and Gocraft/web. Both Revel and Martini have too much dependency injection and other magic to make us feel comfortable. Gorilla is the most minimal.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ruby, Serialization, and Enumeration

Square Engineering — Sun, 25 May 2014 16:06:00 GMT

Written by Xavier Shay.

We came across an interesting Ruby puzzler the other day. Code that had been working fine had started failing during serialization with a scary looking backtrace from within activesupport:

json.rb:128:in `each': not opened for reading (IOError)
  from /gems/activesupport-4.1.1/lib/active_support/core_ext/object/json.rb:128:in `to_a'
  from /gems/activesupport-4.1.1/lib/active_support/core_ext/object/json.rb:128:in `as_json'
  from /ge…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Hello Picasso 2.3

Square Engineering — Fri, 30 May 2014 16:06:00 GMT

Written by D. Koutsogiorgas and Jake Wharton.

Today we are publishing a new version of Picasso, our solution for image downloading and caching on Android. One of the highlights of this release is what we refer to as “request replaying.” Before we showcase it, let’s dig into how Picasso is architected and why that helps us provide cool new fe…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

One Year Later

Square Engineering — Fri, 06 Jun 2014 16:06:00 GMT

Written by Riley Strong.

In the year since I joined, many aspects of my life at Square have changed. Here are a few of my observations.

Growth

The most obvious change is our scale. When I started last April, Square was roughly 450 people. Now we are more than 800; and with our growth, previous structures and systems reached their limits. Physically, the number of our offices grew dramatica…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

iOS Lightning Talk: Open Source Tour

Square Engineering — Fri, 13 Jun 2014 16:06:00 GMT

Written by Jim Puls.

Jim Puls - Profile *Eternally curious.*medium.com

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

iOS Lightning Talk: Register Architecture

Square Engineering — Fri, 13 Jun 2014 16:06:00 GMT

Written by Kyle Van Essen.

Kyle Van Essen - Profile *I work on iOS & Register at @Square. Great software defers to the customer.*medium.com

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square and Girls Who Code

Square Engineering — Tue, 17 Jun 2014 16:07:00 GMT

Written by vanessa slavich.

From June to August, we are hosting 20 local high school students through Girls Who Code’s Summer Immersion Program. Girls Who Code is a national non-profit organization that aims to inspire, educate, and equip young women for futures in the computing-related fields.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Generating Thumbor URLs on iOS

Square Engineering — Wed, 18 Jun 2014 16:07:00 GMT

Written by Jim Puls.

A little while back, we talked about dynamic images with Thumbor.

To recap:

*Thumbor is an open-source, on-demand image service which allows for server-side cropping, resizing, and compositing of images. This is particularly useful for applications where the density and resolution of the target screen can vary wildly. Rather than d…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

OkHttp 2.0

Square Engineering — Mon, 23 Jun 2014 16:07:00 GMT

Written by Jesse Wilson.

OkHttp started as a fork of Android’s HttpURLConnection. That gave us a solid foundation to build upon. Working behind a widely-used API meant that upgrading from AOSP’s HttpURLConnection to ours was easy: just configure URLs stream handler factory.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Advanced Embedding with Square Market

Square Engineering — Wed, 09 Jul 2014 16:07:00 GMT

Written by Jesse Reiss.

We built Square Market to give businesses a way to participate in and navigate the world of online commerce. Particularly those businesses traditionally not part of online commerce, like cafés, restaurants, and bars.

First, we built a way for these types of businesses to take more orders with a comprehensive self-service offering so they could sell food and beverages online for pickup.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s Security Bug Bounty

Square Engineering — Wed, 06 Aug 2014 16:07:00 GMT

Written by Neal Harris.

With so many sellers relying on Square to run and grow their business, we’ve made protecting them a priority. We monitor every transaction from swipe to payment, innovate in fraud prevention, and adhere to industry-leading standards to manage our ne…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Even More Advanced Interactive Menus

Square Engineering — Thu, 07 Aug 2014 16:07:00 GMT

Written by Harris Tsim, Keith Chu, and Matthias Reichenbach.

Three weeks ago, we introduced Menu Embeds to our merchants. Since then, thousands of merchants have embedded their store fronts (aka. “menus”) on their sites to drive sales. We received a lot of great feedback and heard a common theme: make the embed experience even more streamlined and efficient. Today, w…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Summer of Kochiku

Square Engineering — Fri, 08 Aug 2014 16:07:00 GMT

Written by Josh Eversmann.

Kochiku is an open-source tool which automatically partitions test suites into distributable chunks, or shards. Most of Square’s projects use Kochiku to quickly get test results by sharding the work between a few hundred Kochiku-workers running in Amazon EC2. Since the numb…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

College Code Camp III

Square Engineering — Mon, 25 Aug 2014 07:00:00 GMT

Written by vanessa slavich.

Two years ago, we launched our first College Code Camp, a four-day immersion program for women studying computer science. We held our second College Code Camp in January. Inspired by the program, a Square engineer had the idea for High School Code Camp

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Sqrome, a Chrome extension

Square Engineering — Fri, 05 Sep 2014 16:07:00 GMT

Written by Tien Nguyen.

When I joined Square a few months ago, I often ran into email threads where I had no idea who anybody was — thanks to our impressive growth rate and my not-so-impressive memory. Every quarter, Square sets aside a week (we call it hack week), so that everyone has the opportunity to reach outside of their day-to-day projects, and build something that speaks to them personally. I decided this was a perfect time to solve my email problem, and in the process learn how to make my first Chr…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

//TODO: Talk Openly, Develop Openly

Square Engineering — Mon, 15 Sep 2014 16:07:00 GMT

Written by Jake Wharton.

On behalf of Square, I am proud to announce that we are one of the founding companies of //TODO: Talk Openly, Develop Openly, a group dedicated to utilizing and releasing open source software. We all believe we can better improve our open source programs — and our contributions to the open source movement as a whole — by working together.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Trying on Pants

Square Engineering — Tue, 16 Sep 2014 16:07:00 GMT

Written by Eric Ayers.

For the last few months, we’ve been working to migrate some of our build processes to the up-and-coming Pants build tool. We are working to replace some of our uses of Apache Maven.

The Case for Changing Build Systems

Pants is compelling to us for a few reasons. First of all, the overall design was inspired by Google’s internal build system, which we know scales well to large repos containing many projects. Beyond that, its feature set meshes with our needs, including:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Logging can be tricky

Square Engineering — Mon, 22 Sep 2014 16:07:00 GMT

Written by Evan Miller.

At Square, we have a mailing list that we use to discuss extremely technical issues, usually requiring in-depth knowledge of underlying system architecture. We dedicated a group to discuss internals with a focus on learning precisely how and why sys…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Pair of Android Tech Talks

Square Engineering — Fri, 26 Sep 2014 16:07:00 GMT

Written by Jake Wharton.

On Tuesday, Jesse Wilson and I gave Android-themed tech talks in our new Kitchener-Waterloo office. (Thanks to everyone who attended!) We know not everyone can make a trip to Canada on a Tuesday, so we are making the talks available online. Enjoy!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Advocating Against Android Fragments

P-Y Ricau — Wed, 08 Oct 2014 16:07:00 GMT

Recently I gave a tech talk at Droidcon Paris, where I explained the problems Square had with Android fragments and how others could avoid using any fragments.

In 2011, we decided to use fragments for the following reasons:

At this time, we did not yet support tablets — but knew we wanted to eventually. Fragments help build responsive UIs.
Fragments are view controllers; they hold decoupled chunks of business logic that can be tested.
The fragment API provides backstack management, (i.e. it mirrors the behavior of the activity stack within a single activity).

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Our Fourth College Code Camp

Square Engineering — Fri, 10 Oct 2014 16:07:00 GMT

Written by vanessa slavich.

In 12 hours, women engineering students programmed a web page that will help AIDS organization (RED) spread awareness of its mission. After one conversation with Vivienne Harr, the 10-year-old founder of Make a Stand, women engineering students were inspired to program

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Welcome to Square! Let’s Learn D3!

Square Engineering — Mon, 13 Oct 2014 16:07:00 GMT

Written by Zach Margolis.

Recently, I started helping out with Square’s new engineer onboarding program, which we call NEO. NEO covers an engineer’s first 3 weeks at Square. We give these new engineers, or NEObies, a hands-on introduction to the code behind many of Square’s …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Better Parameterized Tests with Burst

Square Engineering — Tue, 21 Oct 2014 16:08:00 GMT

Written by Daniel Lubarov, Jake Wharton, and D. Koutsogiorgas.

At Square, we invest a lot of effort in testing to ensure that our software is reliable. Not only do we unit test our business logic, we also use automated UI tests to detect bugs and prevent regressions in our applications. We also use manual testi…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Learning Ruby

Square Engineering — Wed, 22 Oct 2014 16:08:00 GMT

Written by Eric Strathmeyer.

When I was an undergrad studying computer science, I thought I’d eventually settle on a single programming language, gain mastery, and use that language for the rest of my career. I couldn’t have been more wrong. It seems like I learn a new language…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Human Botnet Part 1

Square Engineering — Fri, 07 Nov 2014 17:08:00 GMT

Written by Tom Daniels.

This is the first in a series of posts from the Square Information Security Team. Over the course of these posts, we’ll detail some of the initiatives we’ve undertaken in order to scale security as the organization grows while still managing our ris…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Anders Hejlsberg Tech Talk on Typescript

Square Engineering — Fri, 21 Nov 2014 17:08:00 GMT

Written by Andrew Kimball.

Anders Hejlsberg, author of Turbo Pascal and lead architect of C# at Microsoft, recently gave a tech talk on Typescript at Square. Typescript is a strict superset of Javascript that adds optional static typing and object-oriented constructs.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Webhooks in the Square Connect API

Square Engineering — Tue, 16 Dec 2014 17:08:00 GMT

Written by Stephen Barlow.

Square’s partners have contributed an expansive collection of app integrations to our platform over the past year. From accounting solutions like Intuit Quickbooks and Xero, to the Fresh KDS kitchen display system, these integrations give merchants even more tools to help them run their business — and they…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Everything I wish I didn’t know about concurrency

Square Engineering — Mon, 12 Jan 2015 17:08:00 GMT

Written by Manik Surtani.

Everything we do as engineers involves concurrency. Thanks to limitations in heat dissipation technology, Moore’s Law hit practical limits over a decade ago and the only way computing has progressed has been to cram more cores onto a die, and/or use more CPUs. And

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing: Our Open Source Code of Conduct

Square Engineering — Tue, 27 Jan 2015 17:08:00 GMT

Written by vanessa slavich.

At Square, we’re committed to contributing to the open source community and simplifying the process of releasing and managing open source software. We’ve seen incredible support and enthusiasm from thousands of people who have already contributed to…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing JavaPoet

Square Engineering — Thu, 29 Jan 2015 17:08:00 GMT

Written by Jesse Wilson.

I used to hate generated code. Early implementations of JSPs, EJBs, and protocol buffers spewed out huge, misformatted files littered with warnings and fully-qualified type names:

*/***
*     * <code>optional string error_text = 2;</code>*
*     */*
    **public** Builder **setErrorText(**
        java**.**lang**.**String value**)** **{**
      **if** **(**value **==** **null)** **{**
  **throw** **new** **NullPointerExceptio…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Our New High School Code Camp

Square Engineering — Mon, 09 Feb 2015 17:08:00 GMT

Written by vanessa slavich.

Two years ago, we learned only 1% of high school girls believed coding would be part of their educational or professional future. We wanted to encourage more young women to pursue STEM and launched High School Code Camp, an eight-month, after-school program designed to prepare young women in San Francisco for the AP Computer Science exam. Square engineers built the computer science curriculum, and over the school year helped the young women

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

SQLBrite: A reactive Database Foundation

Square Engineering — Wed, 25 Feb 2015 17:08:00 GMT

Written by Jake Wharton.

Storing, accessing, and modifying persisted data on Android has been an ever-changing landscape since the platform’s inception. Last year, after evaluating 16 libraries on a spectrum of strict requirements, we determined that nothing existed which m…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

gRPC — cross-platform open source RPC over HTTP/2

Square Engineering — Thu, 26 Feb 2015 17:08:00 GMT

Written by Manik Surtani.

Several months ago, we evaluated open sourcing our proprietary, internal RPC library (which is based on protocol buffers). Along the way, we also decided to move this framework to HTTP/2. Luckily before putting forth too much effort, we learned Google was attempting to open source something similar — and was much further along. We paused our efforts and reached out to Google to see how we could help.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Scaling Square Register

Square Engineering — Thu, 26 Mar 2015 16:08:00 GMT

Written by Kyle Van Essen.

Recently I had the opportunity to write about Register iOS development for objc.io. My article focused on the tools and processes we chose at Square to help scale and streamline the engineering process. If this sounds interesting to you, you can check out the article here:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Our Fifth College Code Camp

Square Engineering — Mon, 06 Apr 2015 16:08:00 GMT

Written by vanessa slavich.

*College Code Camp is our five-day, in-house immersion program for women studying computer science. Spelman student Brianna Fugate shares her experience.*

In January, I had the privilege of participating in Square’s College Code Camp with 22 other women engineering students from all over North America. We were a diverse group with a variety of backgrounds, but we all shared a passion and intellectual …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Protecting infrastructure secrets with Keywhiz

Square Engineering — Tue, 14 Apr 2015 16:08:00 GMT

Written by Justin Cummins.

At Square, our number one priority is security. We needed something to protect secrets, especially as their number increased with our adoption of a service-orientedmicroservice architecture. Although protecting infrastructure secrets is a common need, we weren’t able to find an adequate secret management system. (More on this under

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

LeakCanary: Detect all memory leaks!

P-Y Ricau — Fri, 08 May 2015 16:08:00 GMT

java.lang.OutOfMemoryError
        at android.graphics.Bitmap.nativeCreate(Bitmap.java:-2)
        at android.graphics.Bitmap.createBitmap(Bitmap.java:689)
        at com.squareup.ui.SignView.createSignatureBitmap(SignView.java:121)

Nobody likes OutOfMemoryError crashes

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Open Source Security Bug Bounty

Square Engineering — Mon, 11 May 2015 16:08:00 GMT

Written by Neal Harris.

Today, we’re excited to announce our security bug bounty program for our open source software. We recognize the important contributions the security research community can make when it comes to finding bugs, and we’re asking for your help to report …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

OkHttp’s New URL Class

Square Engineering — Tue, 26 May 2015 16:09:00 GMT

Written by Jesse Wilson.

Android and Java developers have several options when it comes to manipulating URLs:

java.net.URL is 20 years old and shows its age. It works but suffers some implementation problems.
java.net.URI is too strict, because it rejects real-world URLs like this one, and too lenient, because it accepts partial URLs like “”.
android.net.Uri is optimistic: It doesn’t validate its input. This saves unnecessary work in some situations but limits its utility in others.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Week of iOS

Square Engineering — Mon, 01 Jun 2015 16:09:00 GMT

Written by shuvo chatterjee.

At Square, we’re big fans of WWDC. Our iOS developers come together to learn about the latest trends and technologies in iOS, and share best practices with the community. Today, we’re kicking off something new.

This week leading up to WWDC, we’re sharing some of our own best practices and open sourcing several of our iOS projects. And to wrap up the week on June 9, we’re hosting a tech talk. We’ll give demos and present lightning talks (including a continuation of

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Build Stability

Square Engineering — Mon, 01 Jun 2015 16:09:00 GMT

Written by Michael Tauraso.

Every developer at a company that practices continuous integration (CI) has the following conversation at some point about their builds:

Dev 1: “My build failed, but I didn’t change anything related to testSwissCheeseController” Dev 2: “Oh just re-run it. That test has been failing for everyone. It’s not your fault”

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Aardvark: Your Logs Slurped, Your Bugs Licked

Square Engineering — Tue, 02 Jun 2015 16:09:00 GMT

Written by Dan Federman.

The dreaded email

We’ve all experienced the frustration of getting a bug report and not having enough information to track it down. The email hits your inbox: “Hey, I tried to do X and it didn’t work.” There’s no build number, no screenshot, and no explanation of wha…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

[ Space Commader]: Take Command of Objective-C Whitespace

Square Engineering — Wed, 03 Jun 2015 16:09:00 GMT

Written by Alan Fineberg.

Square is releasing [ Space Commander] on GitHub. [ Space Commander] is a set of tools we use to setup, customize, and enforce Objective-C formatting across our Register iOS team, and reclaim time that would be spent manually formatting code.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Valet: A Better Place to Put Your Keys

Square Engineering — Thu, 04 Jun 2015 16:09:00 GMT

Written by Dan Federman and Eric Muller.

Keychain is terrifying

If you’ve ever had to pore over SecItem.h or interact with the Keychain, you’re well aware that it’s a terrifying API. You pass in a dictionary and then you get an error back that lets you know that at least one of your parameters was wrong. Want to…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Dependency Injection: Give Your iOS Code a Shot in the Arm

Square Engineering — Fri, 05 Jun 2015 16:09:00 GMT

Written by Eric Firestone.

What Is Dependency Injection?

Dependency injection (DI) is a popular design pattern in many languages, such as Java and C# , but it hasn’t seen wide adoption in Objective-C. This article aims to give a brief introduction to dependency injection using Objective-C examples, as well as practical methods for using dependency injection in Objective-C code. Although the arti…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Presents: Streamlining Android Apps

Square Engineering — Mon, 08 Jun 2015 16:09:00 GMT

Written by Eric Burke.

On June 25 we’re hosting an Android-themed tech talk at our San Francisco office featuring Jake Wharton and Pierre-Yves Ricau. There will also be time to meet one another over snacks and drinks.

Jake kicks off the event with a talk on “Eliminating Code Overhead,” demonstrating techniques that both libraries and applications can implement to minimize CPU and memory usage.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building Portable Binaries

Square Engineering — Mon, 15 Jun 2015 16:09:00 GMT

Written by Alex Coomans.

Deploying your code is the last major hurdle in getting shiny new features or important bug fixes out to users. However, making sure your application has everything it needs can be a chore. Three typical approaches for preparing your application for…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Stricter Tests for Expectations Set on Nil in RSpec

Square Engineering — Fri, 19 Jun 2015 07:00:00 GMT

Written by liz rush.

When I started on one of my first pieces of code here at Square, I was tasked with making sure a Ruby program from the Data Platform team didn’t continuously retry queries on data when the program hit a non-transient error. Our logs were getting fil…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Application visibility

Square Engineering — Fri, 10 Jul 2015 07:00:00 GMT

Written by Syam Puranam.

Background

Square has experienced tremendous growth over the past five years. Our technology stack evolved from a handful of monolithic rails applications to a microservices architecture. The change and growth in our services brought new challenges for applica…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Dude, Where’s My char[]?

P-Y Ricau — Mon, 20 Jul 2015 16:09:00 GMT

Written by Pierre-Yves Ricau.

This article started as a thread on an internal mailing list and I thought it would also be of interest to people outside of Square.

When Android M preview 2 was released, I started receiving reports of LeakCanarycrashing when parsing heap dumps. LeakCanary reached into the char array of a String object to read a thread name, but in Android M that char array wasn’t there anymore.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Tech Talks — A Peek Into iOS Engineering at Square

Square Engineering — Thu, 23 Jul 2015 16:09:00 GMT

Written by shuvo chatterjee.

During the week of WWDC, we hosted a tech talk to share some of the things we’re doing at Square in iOS engineering. We enjoyed getting to chat with so many of you. For those who weren’t able to attend (or would like to relive the tech talks), we recorded the event and uploaded the videos to Yo…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

iOS Build Infrastructure

Square Engineering — Tue, 28 Jul 2015 16:09:00 GMT

Written by Michael Tauraso.

Square has dozens of iOS engineers working on Square Register. Additionally, Square publishes multiple iOS apps to the App Store and distributes several iOS apps internally. To support the work of our application programmers, we’ve invested in a continuous integration and test cluster.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A small leak will sink a great ship

P-Y Ricau — Thu, 20 Aug 2015 16:09:00 GMT

Written by Pierre-Yves Ricau.

This post started as an internal email thread when I was building LeakCanary. I found a strange memory leak and started digging in order to figure out what was happening.

TL;DR: Prior to Android Lollipop, alert dialogs may cause memory leaks in your Android apps.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Streamlining Android Apps Tech Talks

Square Engineering — Mon, 24 Aug 2015 16:09:00 GMT

Written by Jake Wharton.

Recently, PY and I gave tech talks at our “Streamlining Android Apps” event in Square’s San Francisco office. (Thanks to everyone who attended!) These talks were recorded and are now available on our Square Engineering YouTube channel. Enjoy!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Atlanta is growing

Square Engineering — Thu, 03 Sep 2015 16:09:00 GMT

Written by John LaBanca.

It’s hard to believe that Square’s Atlanta office just celebrated its three year anniversary! Our engineering presence has nearly quadrupled since we planted our roots in July 2012, and it continues to thrive as we hire more engineers to take on additional projects. Today, the enginering team works on infrastructure and helps build tools that sellers use to manage their business and employees. We’re also big fans…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

FieldKit: A Simple Library for Complex Input Formatting

Square Engineering — Wed, 09 Sep 2015 16:10:00 GMT

Written by Joe Taylor and Brian Donovan.

To create the best user experience, we strive to build a beautiful and simple interface for our products. So when we set out to build a checkout flow for our online store, we wanted customers to have the same great experience they’d have on native apps when entering credit card and contact information. This would require a lot of work, but we knew we needed to banish the

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Applications now open: College Code Camp 6

Square Engineering — Wed, 07 Oct 2015 16:10:00 GMT

Written by Alyssa.

This January marks two years since I attended Square’s College Code Camp. Looking back, the most valuable aspect of Code Camp for me was the community we built. My fellow campers were intelligent, passionate, and opinionated, and their interests spa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Presents: Enabling Android Teams

Square Engineering — Thu, 22 Oct 2015 16:10:00 GMT

Written by Eric Burke.

On Tuesday, November 10, we’re hosting an Android event at Square’s San Francisco office with our friends from Slack and Twitter. If you’re in the Bay Area, join us for a night of technical discussion and lightning talks with expert engineers Haley Smith

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Short Guide to Kernel Debugging

Square Engineering — Tue, 27 Oct 2015 16:10:00 GMT

Written by Benjamin Wester.

This article began as an internal email describing a problem that was found on Square’s production hosts. The story is written to serve as an introduction to the tools and practice of debugging the Linux kernel, though it assumes a quite a bit of fa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Even Better Protocol Buffers With Wire 2

Square Engineering — Wed, 28 Oct 2015 16:10:00 GMT

Written by Jesse Wilson.

We’ve been making steady progress on Wire, our implementation of compact, immutable protocol buffers for Android and Java. Today I’m happy to announce Wire 2.0, which further refines our take on what protocol buffers should be.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing git fastclone

Square Engineering — Mon, 16 Nov 2015 17:10:00 GMT

Written by james chang.

Why fastclone?

When your application and organization are growing, module boundaries get redefined. This can take the form of splitting large components, or combining and rewriting several related smaller components. When pursuing these efforts, you may find yours…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Optimizing ruby-protobuf deserialization by 50%

Square Engineering — Mon, 23 Nov 2015 17:10:00 GMT

Written by Zachary Anker.

I’m on a team colloquially called “WebScale” at Square, which deals with extracting legacy payments data from our monorail. One of our recent tasks has been the rollout of a new internal service to search for payments on Square. We mostly use protob…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Enabling Android Teams Tech Talks

Square Engineering — Mon, 30 Nov 2015 17:10:00 GMT

Written by Jake Wharton.

Recently, Haley Smith, Ray Ryan, Ty Smith, and Jesse Wilson gave lightning talks and participated in a panel discussion at our “Enabling Android Teams” event in Square’s San Francisco office. (Thanks to everyone who attended!) These talks were recorded and are now available on our Square Engineering YouTube…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Welcome to the (Color) Matrix

P-Y Ricau — Wed, 09 Dec 2015 17:10:00 GMT

Written by Pierre-Yves Ricau.

This post started as an internal email thread to share a cool trick. I have little formal knowledge on the matter described below and took an empiric approach. Feedback is welcome in the comments!

Specs

I was working on a new screen that showed a downloaded image with a title on top and these constraints:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ace the Square pairing interview

Square Engineering — Mon, 14 Dec 2015 17:10:00 GMT

Written by Logan Johnson.

An engineer friend recently decided to apply to Square and asked me for interviewing tips. Luckily, I do a lot of interviews! I put together some notes, then shared them with other interviewers at Square and asked for comments. This is our collectiv…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ziggurat iOS App Architecture

Square Engineering — Fri, 18 Dec 2015 17:10:00 GMT

Written by Alan Fineberg.

Back in June, I gave a talk on Preventing Massive View Controllers and described an app architecture with a one-way data flow in Swift. At the time, the architecture didn’t have an accompanying blog post or even a name. Now, it has both. I’d like to introduce

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Breaking up with your MonoRail

Square Engineering — Wed, 13 Jan 2016 17:10:00 GMT

Written by Zachary Anker.

At Square, I work on our Payments Scalability team. In 2015, our task was to modernize our payments infrastructure by extracting it from Square/Web, our monolithic Rails app backed by a single MySQL instance. Square/Web has been a core component in …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Shared App Functionality via JavaScript

Square Engineering — Tue, 19 Jan 2016 17:10:00 GMT

Written by Alan Paulin.

When building version 2.9 of the Square Cash app, we ran across an interesting challenge. The app was fetching payment objects from our server that needed to be displayed to the user. This basically involved choosing a template for each payment and formatting the data. For simplicity, let’s say t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Presents: The Journey of Android Engineers

Square Engineering — Tue, 26 Jan 2016 17:10:00 GMT

Written by Eric Burke.

Join us on Thursday, February 18th for the third edition of our Square Presents Series. It’ll be a night of discussion and lightning talks from Square and our friends at Udemy and Highlight. The event starts with lightning talks from John Rodriguez, Effie Barak

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Query Sniper

Manik Surtani — Wed, 27 Jan 2016 22:17:00 GMT

Picture this: your service receives a request and kicks off a database query; the request times out and leaves the query running — leading to an unnecessary database load and possibly starving the database of resources. When services automatically r…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Open sourcing Square’s WomEng Handbook

Square Engineering — Wed, 03 Feb 2016 17:11:00 GMT

Written by Alyssa.

At Square, we have a strong, supportive, and empowering community of women engineers and allies. We come together as a group: WomEng. Our group grew from a mailing list to regular, in-person gatherings. Today, WomEng has expanded outside of Square and includ…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Journey of Android Engineers: Tech Talks

Square Engineering — Thu, 03 Mar 2016 17:11:00 GMT

Written by Jake Wharton.

Recently, John Rodriguez, Effie Barak, Eric Burke, and Christina Lee gave lightning talks and participated in a panel discussion at our “Journey of Android Engineers” event in Square’s San Francisco office. (Thanks to everyone who attended!) These talks were recorded and are now available on our

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Vulnerability in OkHttp’s Certificate Pinner

Square Engineering — Fri, 11 Mar 2016 17:11:00 GMT

Written by Jesse Wilson.

Security researcher John Kozyrakis from Cigital recently discovered a vulnerability in OkHttp’s CertificatePinner. He responsibly disclosed the issue to us via Square’s open source bug bounty program at HackerOne.

After feeling just a little bit embarrassed, I implemented a fix and released it as OkHttp 3.2.0. We also backported the fix to OkHttp 2.7.5. If you’re using OkHttp in your application, please upgrade to the latest release.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Framed Data Team Joins Square

Square Engineering — Mon, 14 Mar 2016 16:11:00 GMT

Written by Jacqueline Reses.

From the early days of Square, we built a discipline in data science that allowed us to take a differentiated approach to risk management, and thus reduce the barriers to entry for our sellers to accept credit cards. Our data scientists are constant…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Square’s Register API and E-commerce API

Square Engineering — Wed, 30 Mar 2016 16:11:00 GMT

Written by Jianliang Zhao.

Have you ever looked at Square’s hardware offerings (maybe our newest EMV and NFC card reader) and thought, “I could build something amazing using that”? Historically, payments and hardware development were often associated with archaic and difficul…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Android Spring Cleaning Tech Talks

Square Engineering — Fri, 08 Apr 2016 16:11:00 GMT

Written by Jake Wharton.

Recently, John Rodriguez, Lisa Neigut, Jake Wharton, and Lisa Wray gave lightning talks and participated in a panel discussion at our “Android Spring Cleaning” event in Square’s New York City office. (Thanks to everyone who attended!) These talks were recorded and are now available on our Square Engineering YouTub…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

pair, a git author tool

Square Engineering — Wed, 13 Apr 2016 16:11:00 GMT

Written by Brian Donovan.

Software engineers at Square sometimes write code by themselves, and sometimes with others. When we write code with others at the same computer we call that “pair programming” or “pairing”. We use this technique in our interviews, and in our work when appropriate. When we’re ready to commit our work in our version control system, git, we want to ensure that all the authors are listed for posterity.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Shift — Safe and Easy Database Migrations

Square Engineering — Fri, 15 Apr 2016 16:11:00 GMT

Written by Michael Finch.

Shift is an application that makes it easy to run online schema migrations for MySQL databases. We use it at Square to run thousands of databases migrations every month. Today we are happy to be open sourcing the project, which can be found on GitHu…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

iOS 9 upgrade: Why did my unit tests grind to a halt?

Square Engineering — Wed, 27 Apr 2016 16:11:00 GMT

Written by Alan Fineberg.

While upgrading Square Register from iOS 8 to iOS 9, we found that our unit test behavior changed in a way that was difficult to diagnose. We investigated the issue and retraced our steps to arrive at the root cause. Ultimately we found that the und…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Tailoring Pants for Square

Square Engineering — Mon, 02 May 2016 16:11:00 GMT

Written by Eric Ayers.

This week, the Pants project announced a 1.0 release of the open source Pants Build System. The 1.0 release of Pants indicates that the tool is ready for more widespread adoption.

Square is a proud contributor to Pants. Developers at Square have been using and contributing to Pants since 2014 to develop our Java services. When we first joined the project, we found a tool that required lots of customization and insider knowledge to install and operate. Today the tool has a streamlined installation process, extensive documentation, a clea…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Content Security Policy for Single Page Web Apps

Square Engineering — Thu, 19 May 2016 16:11:00 GMT

Written by Terrill Dent.

This week we fully enabled CSP on cash.me. It’s been months in the making and the result is a safer experience for all our customers. This is how we did it.

Implementing Content Security Policy (CSP) on an established website is like flipping over a rock while you’re on a hike, exposing a world of creepy crawlers that you know are there but don’t really expect. It surfaces all the connections, sources, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Square’s Register API for Android

P-Y Ricau — Wed, 25 May 2016 16:11:00 GMT

Written by Pierre-Yves Ricau.

Following our launch of Register API for iOS in March, beginning today, developers can now build custom Android point-of-sale applications that take swipe, dip, or tap payments through Square hardware, and integrate with Square’s software and services. This builds on our existing API offering…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

XCKnife: faster distributed tests for iOS

Square Engineering — Tue, 07 Jun 2016 16:11:00 GMT

Written by Daniel Ribeiro.

At Square, we highly value the efficiency of our engineers. As our codebases grow and our test suite reaches tens of thousands of tests, our engineers wait longer and longer for their builds to be green in our Continuous Integration system.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Caviar iOS: Migrating from AdvancedCollectionView to PJFDataSource

Square Engineering — Mon, 13 Jun 2016 16:11:00 GMT

Written by Michael Thole.

In December 2014, we released the first version of our iOS app for Caviar, our high quality restaurant delivery service. The view controller architecture of the app was largely based on the framework laid out in Apple’s 2014 WWDC Talk: Advanced User Interfaces with Collection Views

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Cleanse: A Lightweight Dependency Injection Framework For Swift

Square Engineering — Tue, 14 Jun 2016 16:11:00 GMT

Written by Mike Lewis.

Dependency Injection for All (Mobile Devices)

Several years ago, I was introduced to dependency injection(DI) working on a Java service here. Our Java “Service Container” is built on top of Guice. After a small learning curve, it clearly became one of those technologies I couldn’t live without. DI enables software to be

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

SuperDelegate: The Better App Delegate

Square Engineering — Wed, 15 Jun 2016 16:11:00 GMT

A Swift framework that provides a consistent and bug-free App Delegate API across all iOS SDKs.

Written by Dan Federman.

We deserve better

If you’ve written an iOS application, you’ve implemented a UIApplicationDelegate. UIApplicationDelegate is central to how our apps interact with iOS, but the API is incredibly idiosyncratic. When an app is launched due to a Quick Action via 3D Touch…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Valet Beats the OS X Keychain Access Control List Zero-Day Vulnerability

Square Engineering — Sun, 19 Jun 2016 16:12:00 GMT

Written by Dan Federman.

The world is on fire

On June 17th, The Register reported that there was a zero-day vulnerability in the iOS and OS X Keychain that compromised secure data stored in the Keychain. The article claimed that data written to the keychain could be read by a malicious application. At Square, we write iOS code t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square WomEng Hear + Now Tech Talks: June 2016

Square Engineering — Tue, 26 Jul 2016 16:12:00 GMT

Written by Marie Chatfield.

Square WomEng hosts a quarterly lightning talk series, Hear + Now, that gives a voice to accomplished engineers across the tech industry. Women, genderqueer, trans, and nonbinary engineers and allies are welcome and encouraged to attend.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s First-Ever Hack Night

Square Engineering — Tue, 02 Aug 2016 16:12:00 GMT

Written by Jonathan Andrew Wolter.

On July 19th, Square held its “Hack Night 0”, where teams competed to build on Square’s growing commerce platform using its existing and newly-released APIs.

Winner Ethan Fan’s creation, “Chatbot Ordering”, integrated with Square’s Items, Inventory and Register APIs to enable users to order ahead from a favorite food truck or restaurant by messaging a chat bot on Slack, then head straight to the register for quick pickup.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Careers

Square — Wed, 10 Aug 2016 00:40:09 GMT

Square creates products and services that push boundaries and innovate business. We’re looking for curious, hard-working leaders to join our team and help empower our global community of sellers. Have an idea? Pitch it — entrepreneurial minds thrive…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Stay Connected

Square — Wed, 10 Aug 2016 00:41:13 GMT

Square.com
@Square, @SquareCareers, and @SquareEng on Twitter
Square on GitHub
Caviar’s blog on Medium

Try Caviar *Caviar is the easiest way to order from America’s best independent restaurants. We partner directly with restaurants to…*caviarfeed.me Square Corner Blog *As Square engineers, we regularly contribute to the open source community and enjoy sharing our thoughts on algorithms…*medium.com

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

About Square Engineering

Square Engineering — Wed, 10 Aug 2016 00:44:11 GMT

Square began with a simple idea: everyone should be able to accept credit cards. We’ve been rethinking buying and selling ever since.

For sellers, we’re creating one cohesive service to run your entire business, from a register in your pocket and analytics on your laptop, to small business financing and marketing tools that drive new sales. For buyers, we’re making it faster to or…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Upgrading a Reverse Proxy from Netty 3 to 4

Square Engineering — Tue, 09 Aug 2016 16:12:00 GMT

Written by Chris Conroy and Matt Davenport.

Tracon: Square’s reverse proxy

Tracon is our reverse HTTP proxy powered by Netty. Several years ago, as we started to move to a microservice architecture, we realized that we needed a reverse proxy to coordinate the migration of APIs from our legacy monolith to our rapidly expanding set of microservices.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

gRPC reaches 1.0

Manik Surtani — Mon, 22 Aug 2016 18:10:03 GMT

Last year, in collaboration with Google, we introduced gRPC to the world. Internally, the Traffic Engineering team at Square has been working on integrating gRPC with Square’s infrastructure — I recently presented some of our work:

Over the course of a year of active development, we’ve seen a fast-growing community, a repository of contributions, and even get-togethers in meatspace.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Optimizing Ember Templates

Terrill Dent — Wed, 31 Aug 2016 16:27:18 GMT

Update: Ember’s base performance has improved a lot since this article was first published! Ember 2.10 shipped with a new rendering engine that makes some of these optimizations unnecessary. If you’re working on an older app, 2.9 or less, keep readi…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Empowering Businesses: What It’s Like to Intern at Square

Raymond Yin — Tue, 13 Sep 2016 19:52:17 GMT

I worked on the web app for Square Appointments, an online scheduling tool that helps sellers manage their appointments. Imagine a hair salon with multiple locations, numerous employees, varying hours of business, and hundreds of appointments daily.…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Becoming a Well-Rounded Square

Elana Tee — Tue, 13 Sep 2016 18:10:41 GMT

A couple weeks ago, I had the opportunity to hang out at Square’s New York City office with 16 other talented women engineers for Square College Code Camp, a five-day immersive program for women studying engineering that focuses on developing technical and leadership skills.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Brief Guide to Square’s Product Manager Intern Program

Tyler Sanchez — Wed, 14 Sep 2016 20:20:25 GMT

Two weeks ago was my last day as a Product Manager intern at Square. The summer went quickly and I wanted to share some thoughts in hopes that they may be useful to others hoping to break into the world of Product Management. Soon I’ll be heading ba…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing the Vendor Security Alliance

Samantha Verdile — Thu, 15 Sep 2016 15:22:47 GMT

At Square, we protect data like our business depends on it — because it does. We adhere to industry-leading standards to manage our network, secure our web and client applications, and set policies across our organization.

We believe our external partners should follow the same standards to which we ourselves adhere. We dedicate significant time and resources to vetting vendors: reviewing their policies, providing feedback, and pushing for stricter and stronger standa…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Android leak pattern: subscriptions in views

P-Y Ricau — Tue, 20 Sep 2016 00:55:57 GMT

In Square Register Android, we rely on custom views to structure our app. Sometimes a view listens to changes from an object that lives longer than that view.

For instance, a HeaderView might want to listen to username changes coming from an Authenticator singleton:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Low Power Mode: Managing Your Emotional and Creative Energy

Marie Chatfield — Sun, 02 Oct 2016 05:02:10 GMT

Low Power Mode: managing your emotional and creative energy. @mariechatfield // Art Credit: “Crocodile” by Gwenn Seemel, licensed under CC BY 2.0

Good afternoon! My name is Marie Chatfield, and I am so honored to be here with you today. I’m originally from Houston, and now live in San Francisco, where I work on a front-end infrastructure team at Square.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Bikeshop

Ella Polo — Wed, 05 Oct 2016 20:06:33 GMT

When I joined the Developers team at Square a few weeks ago, I was told that, as part of onboarding, every new team member makes a sample application using our APIs. Rich sample applications are great because they not only show developers how the AP…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

No Cause for Concern — RxJava and Retrofit Throwing a Tantrum

P-Y Ricau — Wed, 02 Nov 2016 19:47:30 GMT

Last week, we found an interesting API design issue in the Throwable class of the JDK that led to bugs in RxJava and Retrofit. This is a write-up of how we found those bugs.

Assembly tracking

Monday morning, Nelson Osacky opens a pull request to enable RxJava Assembly Tracking in the debug build of Square Register Android.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Advice from the Insider: Landing Your Dream Engineering Job

Remi Levoff — Wed, 09 Nov 2016 19:11:43 GMT

This blog post originated from a presentation originally given by Alyssa Pohahau at Barnard College.

When it comes to scoring a full-time position as an engineer, it’s no secret that competition is fierce. That said, if joining an innovative, cutting-edge community of sharp minds strikes your fancy, a bit of prep and determination will serve you we…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Inclusion up and to the right: how we’re improving Hear + Now tech talks

Marie Chatfield — Thu, 10 Nov 2016 19:30:58 GMT

tl;dr Square WomEng cares about inclusion, which is why we’re acknowledging how our tech talk series Hear + Now has failed to be as inclusive as we’d like, and committing to improvements.

Hear + Now is a quarterly tech talk series hosted by Square WomEng. When we first started Hear + Now a year ago, we were focused on creating a space for engineers who identified primarily as women to have their voices heard. We’ve had some really amazing women speak about their experiences and their areas of expertise

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New York Tech Talk Videos

Jake Wharton — Thu, 10 Nov 2016 21:50:05 GMT

Recently, Ron Shapiro and David P. Baker from Google joined me to present a pair of tech talks in Square’s New York City office. (Thanks to everyone who attended!) These talks were recorded and are now available on our Square Engineering YouTube channel. Enjoy!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing enhancements to Square’s Register API

Marylise Tauzia — Fri, 02 Dec 2016 22:26:59 GMT

Square has released a set of new features and enhancements to its developer platform. These enhancements are part of the Register API and include:

The ability to pass a Customer ID to a register app and keep the customer’s card details on file;
Removing the requirement to build out the OAuth flow for merchants using a developer app; and
Android Web API.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Web Sockets now shipping in OkHttp 3.5!

Jake Wharton — Fri, 02 Dec 2016 14:00:01 GMT

Unlike the traditional request/response model of HTTP, web sockets provide fully bi-directional streaming of messages. This means that both the client and the server can send any number of messages to the other peer at any time. With today’s version…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Developer Night Recap

Tristan Sokol — Mon, 05 Dec 2016 21:46:37 GMT

A few weeks ago, we invited a small group of local developers to come visit the Square offices and take a figurative peek behind the curtains to see how our APIs are made, and what we are working on in the near future.

We’re so excited about the things we are working on that we wanted to share them publicly—so everyone who is building with Square can share in our excitement!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Anonymous Sandbox

Tristan Sokol — Thu, 08 Dec 2016 19:06:27 GMT

You might have noticed that we have a new section in the sample code section of our API reference. Say hello to your new Anonymous Sandbox!

We created what we call Anonymous Sandbox to make it easy to try out and explore the functionality of our APIs. You can find your credentials at the top of the page in our API Reference, which allow you to interact with a sandboxed environment without logging in or creating a Square account. We made these credentials persistent, so you should be able to use the exact same credentials the next time you visit the documentation.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Looking Back on the Grace Hopper Celebration

Square Engineering — Fri, 09 Dec 2016 21:02:01 GMT

This fall, 25 Squares attended The Grace Hopper Celebration of Women in Computing (GHC). The event may have concluded in October, but the learnings from GHC continue to impact Squares. Gloria Kimbawala and Rodion Steshenko took time to reflect on their personal experiences at GHC. Read on for more details.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The traits you need as a Product Manager that you won’t find in job descriptions

Koun Han — Fri, 06 Jan 2017 21:39:50 GMT

You’ve read the job descriptions, familiarized yourself with the responsibilities, and understand where PMs fit in at a company. But what really makes a successful PM?

Almost all job descriptions for tech company Product Managers (PM) have something similar to the following:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How a Square developer is helping small business owners wear their favorite hat

Marylise Tauzia — Tue, 10 Jan 2017 16:47:38 GMT

The Inspiration

It all started when Donovan Janus’ wife, Allison, decided to pursue her true passion of photography. When she started a photography business in 2011, business took off immediately. The problem was that, while an exceptional photographer, she didn’t …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Product managing an integrated hardware product at Square

Koun Han — Mon, 20 Feb 2017 20:59:16 GMT

The PM perspective: Pivoting from software to hardware

I am a lead Hardware Product Manager at Square, where I’ve worked most recently on our contactless and chip reader. But when I started at Square 3 years ago, I worked on pure software products (as I had also done for 6 years previously at Facebook). I’ve always loved that Square provides an integrated solution to small businesses with both hardware and software…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square at WeCode Harvard

Square Engineering — Wed, 01 Mar 2017 00:21:20 GMT

By Saqi Mehta

Earlier this month, I had the privilege to again attend **WeCode Harvard** at Harvard University. Each year, the conference — which stands for Women Engineers Code — brings together 500 women from around the world who are passionate about technology and entrepreneurship. The weekend was filled with incredible activities…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Taking Our Show on the Road

Tristan Sokol — Thu, 02 Mar 2017 22:22:57 GMT

Come meet members of our team and learn more about our APIs at some upcoming events across the country!

FowardJS/ForwardSwift

Our first stop was at the local ForwardJS/ForwardSwift conferences here in San Francisco on March 1st & 2nd. We had a few Squares in attendance to learn about the upcoming technologies in Javascript and Swift, as well as a booth where we discussed some of the new features of our APIs and even some of o…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ok Google, Charge $2 for Coffee

P-Y Ricau — Fri, 10 Mar 2017 21:54:16 GMT

When I received my Google Home, I immediately felt the urge to build something with it. After a good night’s sleep, I had an idea: Baristas and business owners usually have their hands full behind the counter. What if they could complete transaction…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Incident Summary: 2017–03–16

Square Engineering — Fri, 17 Mar 2017 20:13:05 GMT

Authors: Erik Bourget, Toby Reyelts, and Xavier Shay

On March 16, beginning at 10:02 a.m. PDT, Square’s serving infrastructure experienced a service disruption. Most of Square’s products and services were affected in this outage, including payment processing, Point of Sale, Dashboard, Appointments, an…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Getting started with Postman and Square’s APIs

Tristan Sokol — Wed, 22 Mar 2017 23:15:49 GMT

Step 0: Install Postman

Before you can use Postman, you need to install it. Visit https://www.getpostman.com/ and download the preferred version for your system.

Step 1: Get the Postman collection

This step is easy. Just click on the big Run in Postman button on this page and you’ll be prompted to import the collection inside of Postman. You can also find this button in the Square API documentation.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Anatomy of an HAProxy <-> Java TLS bug

Steven Davidovitz — Mon, 27 Mar 2017 19:23:27 GMT

TL;DR: Java interprets the TLS specification strictly and does not allow session resumption when the connection is closed uncleanly.

While deploying an internal load balancing project based on HAProxy to our staging environment with a configuration that included 100s of services and backends, HAProxy immediately pegged CPU usage at 100%. Since there was no traffic flowing through…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Moshi, another JSON Processor

Jesse Wilson — Mon, 27 Mar 2017 19:50:19 GMT

It’s rare for a programmer to get to work on the same problem twice. Either the first is good enough and you’re done, or it wasn’t and you’re foolish to try again. Circumstance and hubris have given me two opportunities to make another attempt.

Guice, a Dependency Injector

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Build with Square is creating waves in Australia!

Marylise Tauzia — Tue, 28 Mar 2017 23:09:00 GMT

Since the U.S. launch of Build with Square in March 2016, Square has been committed to bringing our tools to more developers and sellers of all sizes. Our collection of APIs enable developers to build custom solutions for sellers to empower them to …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

See Square in the Northeast and learn about our APIs

Tristan Sokol — Thu, 13 Apr 2017 19:14:27 GMT

In April, we are going to show some love to Boston, Baltimore, and New York, and we would love to see you at some of these events!

Droidcon Boston

First off, we will be at Droidcon Boston, one of the best community-driven Android conferences, on April 10th & 11th. It is being hosted in Boston this year for the first time ever, and we’ll be there showing off our Android point of Sale API and ou…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How Square writes commit messages

Logan Johnson — Tue, 18 Apr 2017 17:51:45 GMT

Commit messages are an important form of communication for us at Square, so writing them well is a great way for us to give time back to each other. Often we wish we’d done a better job earlier. The commits from those days are still in our history, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Improving the Square Register API Payment Experience

Gabriel Jinich — Tue, 25 Apr 2017 01:00:19 GMT

We recently introduced new functionality in the Square Point of Sale iOS and Android apps that greatly improves the payment experience when using Register API.

On iOS, we’ve added functionality that keeps your Square contactless & chip card reader connected in the background (note: this is already available on Android). And, on Android, we’ve enabled a transparent background for Register API customers.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing new versions of our client SDKs

Tristan Sokol — Fri, 28 Apr 2017 22:18:28 GMT

[Update: the beta is now over; you can download the most up to date versions of our client SDKs here.]

At Square, we want to make building integrations with our platform as fast and easy as possible. To help with that, we are working on a big update to our SDKs to expand their functionality and make them even easier to use. We are also launching a Sl…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How to install Square’s beta SDKs

Tristan Sokol — Tue, 02 May 2017 22:34:15 GMT

[Update: the beta has completed, download the latest version of our SDKs here] As a reminder, if you want help with installation, to give us feedback on the new design and features, or simply to learn more about the APIs, request an invite to our new

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Setup up HTTPS for your e-commerce site with Let’s Encrypt and Google App Engine.

Tristan Sokol — Tue, 09 May 2017 00:37:36 GMT

Security on the web is hugely important, especially when someone is trusting you with their payment card information. Even though Square handles the complex parts of PCI compliance for you, we do require your e-commerce forms to be served from an HT…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Rolling out @Nullable

Jesse Wilson — Fri, 12 May 2017 16:26:05 GMT

Lots of us have strong opinions on null. I don’t think it’s evil, or that using null is sloppy. I just want to be deliberate: wherever a parameter or return value can be null, the interpretation of that should be explicit.

/** 
 * Consumes the next line of text and returns it.
 * Returns null if there are no more lines. 
 */
String readUtf8Line() throws IOException;

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Open Source ♥s Kotlin

Jake Wharton — Fri, 12 May 2017 15:25:04 GMT

Consumers of Square’s open source libraries may remember our “Seven Days of Open Source” prior to Google I/O 2013. We released major versions of some of our projects in the days leading up to the event. This culminated in us also having a booth inside the developer space at I/O and getting to meet and chat with you all about those proj…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Non-null is the Default

Jesse Wilson — Sat, 13 May 2017 17:27:56 GMT

IntelliJ warns about potential NullPointerExceptions

The @Nullable imposes an obligation on the consumers of the value: they must prepare for it to be null. But what happens when I’m the one producing the value? Suppose that I’m calling the method above.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

An Optional’s place in Kotlin

Jake Wharton — Sun, 14 May 2017 16:18:21 GMT

With nullability being a first-class citizen in Kotlin’s type system, the need for an Optional type seems all but diminished. Just because you can explicitly express nullability, however, does not mean that null is always allowed.

For example, Retrofit provides adapters for RxJava 1.x and 2.x which allow modeling your requests as a single-element stream.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Kotlin’s a great language for JSON

Jesse Wilson — Mon, 15 May 2017 17:28:26 GMT

Though it has its wrinkles, I really like JSON. It’s easy to read, pretty fast to parse, and refreshingly simple. Here’s a sample message from GitHub’s exemplar API:

{
  "url": "https://api.github.com/repos/square/okio/issues/156",
  "id": 91393390,
  "number": 156,
  "title": "ByteString CharSequence idea",
  "state": "open",
  "created_at": "2015-06-27T00:49:40.000Z",
  "body": "Let's make CharSequence that's …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Generating Kotlin code with KotlinPoet

Jake Wharton — Tue, 16 May 2017 16:36:46 GMT

Java code generation has become a popular solution to simplifying library code. Dagger generates interface implementations, Butter Knife generates Android UI boilerplate, and Wire generates implementations of value classes for binary encoding of data.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Washington, DC Taxis Are Moving to New Digital Meter Apps That Connect with Square

Marylise Tauzia — Wed, 17 May 2017 13:15:48 GMT

Most taxis are still running outdated, legacy metering hardware that doesn’t integrate with the point of sale or credit card reader. As technology changes the way we pay, taxis have to be able to innovate quickly and keep up with technology shifts.

Today, Washington, DC’s Department of For-Hire Vehicles (DFHV) announced that all the city’s taxis will shift to new apps to replace antiquated payment terminals and legacy metering hardware. We’re proud that Square will be powering the first digita…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using Square’s REST APIs to Build a Sandbox Dashboard Part 1: Authentication & Locations.

Tristan Sokol — Thu, 18 May 2017 23:05:43 GMT

initial sketch… or entry in world’s worst handwriting contest?

Building the Square Dashboard

At Square, there is a whole team dedicated to our Dashboard, and I’m not going to get close to replicating all the work they have done. I will however start with some boilerplate HTML that sets up the general structure of the page, as well as some J…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building Jukebox: A viral way to share music when a simple text, meme, or gif isn’t enough

Marylise Tauzia — Fri, 19 May 2017 22:32:29 GMT

Eric King and Damola Omotosho are two old friends who met at Virginia Tech while earning their engineering degrees. After graduation, they both ended up pursuing a master’s degree in engineering before working full-time in tech. While they were off …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing the new Square Catalog API

Matan-Paul Shetrit — Tue, 23 May 2017 17:28:21 GMT

Exposing APIs which allow our partners to build meaningful and delightful experiences for Square sellers is fundamental to meeting the needs of our diverse community of sellers. For most sellers their item library is critical to their success, so wh…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Code Camp Takes Atlanta

Square Engineering — Wed, 24 May 2017 18:40:18 GMT

Code Camp — Square’s immersion program for college women interested in pursuing careers in tech — is coming to Square’s Atlanta office for the first time!

We developed Code Camp five years ago in San Francisco, then took it to New York City, and are excited to expand to another city that’s integral to our robust engineering team. In August, participants will join us in our Atlanta office for five life-changing (so we’ve heard!) days of coding workshops, leadership sessions, and networ…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square’s Register API is now Point of Sale API

Gabriel Jinich — Tue, 30 May 2017 20:20:13 GMT

We recently announced a new name for the Square Register app to better reflect everything it can do to help run your business: Square Point of Sale. You can use the app to take payments, track sales, manage customers and employees, and more — everything you need from a complete point of sale.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Five Ways to Make the Most of Your Internship

Saqi Mehta — Thu, 08 Jun 2017 17:20:49 GMT

Each summer we see an infusion of fresh energy in the office, which means that intern season has officially kicked off! The Bay Area increases by a few thousand students looking to work on some of the most challenging but intellectually satisfying p…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Text for your sales reports using Twilio Functions and Square

Tristan Sokol — Fri, 09 Jun 2017 19:54:35 GMT

The Idea

When building an application for your business (or many businesses) notifications are an important layer to that experience. Twilio has a number of products that allow you to add communications and messaging to your app, but we tried out out the new…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

RRULE expansion in Ruby

Ryan Mitchell — Mon, 12 Jun 2017 17:39:41 GMT

On the Square Appointments team, we often need to deal with events that repeat — from simple cases (like a weekly lunch meeting) to more complex ones (like a haircut every other month on the second-to-last Tuesday, except for September 19th). Fortun…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building a Sandbox Dashboard Pt. 2: Adding a Transactions List

Tristan Sokol — Fri, 16 Jun 2017 18:52:40 GMT

At the end of the last post, we created a basic copy of your Square Dashboard that was able to retrieve your location information. In this post we’ll use Square’s transaction reporting APIs to list out completed transactions within the sandbox accou…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Faster App Recovery With Bounded Queues

Zachary Anker — Wed, 21 Jun 2017 18:08:07 GMT

A problem we’ve encountered in the past is when a Ruby app becomes unresponsive due to downstream issues. After the issue is resolved, the app continues to be unresponsive or very slow to process requests. While a restarts clear it up immediately, b…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Square Checkout

Matan-Paul Shetrit — Thu, 22 Jun 2017 16:13:34 GMT

Over a year ago we introduced Build with Square, our online and offline payment platform alongside our reporting APIs. Since then, we’ve worked closely with developers and our sellers to identify how we can make it easier to start selling online while harnessing the power of our APIs. One of the pieces of feedback we keep hearing from sellers is:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

ActiveMerchantSquare for Square’s e-commerce API

Francisco Rojas — Mon, 26 Jun 2017 18:29:08 GMT

We released ActiveMerchantSquare for developers who want to use Square’s e-commerce API with the ActiveMerchant rubygem. If you are a ruby developer you may use the popular ActiveMerchant gem as a common abstraction layer (in production use since 2006) to work with many payments gateways.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Leadership, Management, and Tribes

Alan Paulin — Mon, 26 Jun 2017 19:17:59 GMT

There are a lot of great books about leadership and management. One is *Tribes* by Seth Godin, which is a great read for any aspiring leader. Tribes talks a lot about leaders versus managers and, as an Engineering Manager, it got me thinking about my own views on leadership and management. Every organization needs great leaders as well as great managers, but are they the same people? And what r…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

No Billing Postal Code? No Problem!

Matan-Paul Shetrit — Thu, 06 Jul 2017 17:23:35 GMT

As Square’s eCommerce platform expands outside the United States and Canada, we’ve heard feedback from developers in other countries (e.g. Japan & Australia), where requesting billing postal codes is uncommon, that they’d like to remove the postal code field in their

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Paralayout

Peter Westen — Thu, 06 Jul 2017 19:03:01 GMT

You know the feeling: the design spec comes in, polished and perfect, and you know at a glance that you’ve got two ways to go:

implement precisely to spec, but with a horrific mess of code and UI configuration behind it (and probably a couple of days late) or
ship on time, with a simpler implementation that gets the UI, you know, mostly right — and avoid looking at yourself in the mirror the next morning.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Always Be Closing

Alec Holmes — Tue, 11 Jul 2017 19:31:01 GMT

This is the story of a resource leak in one of Square’s Go services and the process of uncovering the root cause. Facing spiky and mysterious system metrics, we used a variety of standard and homemade tools to uncover a subtle bug in one of our core…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Surfacing Hidden Change to Pull Requests

Jake Wharton — Thu, 13 Jul 2017 19:34:14 GMT

Programming frequently deals in visible changes: the logic in your code, the dependencies you declare, the API you expose. There is, however, quite a bit of associated hidden change: transitive dependencies, generated code, and manifest files.

In code review we focus on the visible because that is what is presented to us in the diff.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Recurring charges with PHP and Card on File

Tristan Sokol — Thu, 20 Jul 2017 17:01:41 GMT

Whether you have a subscription service, or regular clients that you want to charge repeatedly, you can use Square’s e-commerce APIs and Card on File.

Keeping a customer’s card on file is almost identical to charging it with Square’s e-commerce APIs. The key difference is that instead of submitting a card nonce to a the charge endpoint, you attach it to a customer and then submit that customer’s attached card to be charged.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How Square makes its SDKs

Tristan Sokol — Fri, 28 Jul 2017 23:00:00 GMT

The developer platform team at Square is a little different than most. Rather than build separate APIs for our developer products, we focus on exposing the APIs that our first-party product use to create a seamless experience for developers. We have…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square WomEng Hear + Now Tech Talks: July 2017

Meghan McNeil — Tue, 01 Aug 2017 01:21:36 GMT

Lightning talks on the theme “Nerd Out Loud.”

We just wrapped up another edition of Hear + Now, Square’s quarterly series of lightning tech talks that we offer to marginalized groups as a non-intimidating space to present.

After one of our WomEng members attended AlterConf, we decided to open up the speakers to anyone who identifies as belonging to a marginalized group (and wrote a blog post explaining these changes).

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Coffee Shop Kiosk

James Smith — Tue, 01 Aug 2017 23:00:04 GMT

When I joined the Developers team at Square, the first thing I did was build an application that uses our APIs. Every new engineer on the team does this (you can read about my colleague’s example Android app here) so that we can walk in our customers’ shoes. It’s become a great tool to reinforce feedback from developers when building real world applications. For my project, I chose to build a customer-facing kiosk application as we’re seeing more and more d…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Peek into Machine Learning at Square

Sara Vera — Fri, 04 Aug 2017 17:34:16 GMT

We’ll be posting more about specific projects, methods, and how we use machine learning in our day-to-day work — stay tuned! For now, here’s a glimpse into machine learning at Square.

Square has a large, unique data set that covers businesses across the U.S., Canada, Australia, Japan, and the UK. Machine learning is a key way we are taking a data-driven approach to automating both our internal tools and customer-facing experience…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Deep Dive on Ember Events

Marie Chatfield — Tue, 08 Aug 2017 20:41:09 GMT

A few days ago, I was working on a really exciting new feature. As part of rolling out these changes, I implemented an onboarding tour — a sequence of tooltips that teach users how to interact with the different parts.

I made one small change to a template in one of our Ember apps, and everything broke. Can you guess what happened?

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Sandbox Dashboard part 3: Customers

Tristan Sokol — Fri, 11 Aug 2017 17:25:01 GMT

This is the third post in our series illustrating how to make a dashboard for your sandbox developer account. For more context, take a peek at Part 1 and Part 2.

In previous posts, we added the ability to view location information as well as a full record of all transactions. For the third installment of our Sandbox Dashboard series, we’ll add functionality to display and interact with our sandbox customers. Let’s take a look at where we ended up last time:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Live from Atlanta: Square Code Camp 2017

Jackie Reses — Tue, 15 Aug 2017 05:21:10 GMT

This week, Square’s Atlanta Office welcomes 13 college-aged women pursuing careers in engineering.

We launched Code Camp in 2012 to inspire, educate, and empower the next generation of women in technology. Today we’re kicking off the inaugural Code Camp Atlanta, and we’re excited to show off a Square office that’s integral to our robust engineering team.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Debugging a series of miscalculations in osquery

Vishwa Shah — Fri, 18 Aug 2017 18:59:37 GMT

What is osquery?

osquery is an an open source tool by Facebook that provides a SQL interface for system information.

Over the course of the summer I’ve been working on integrating osquery results into our internal asset tracker for automation/validation purposes. It’s been incredibly useful for monitoring various stats, and the SQL interface makes it easy to use.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Easing your development with ngrok

Tristan Sokol — Mon, 21 Aug 2017 19:09:04 GMT

ngrok let’s you easily test your local code, webhooks & more with one a simple command.

Last week I was working on a presentation for PDX PHP about how to accept in person payments using a PHP-based point of sale and Square’s APIs. Most PHP development workflows involve using a local development server and then pushing to your producti…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building web-based points of sale for Android & iOS

Tristan Sokol — Fri, 25 Aug 2017 19:36:37 GMT

In order to make a cross platform web app, we need logic to detect what platform the target device is running. Doing this accurately can be *really hard, *and there are whole libraries dedicated to parsing out user agents. To keep this example simpl…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Version 2.2.1 of our SDKs Are Now Live

Tristan Sokol — Tue, 29 Aug 2017 21:59:48 GMT

If you want to better understand how we make our SDKs, and how our API specification works with templates to create a complete SDK, check out How Square makes its SDKs. Below we’ll get into what’s new and improved in version 2.2.1 of our SDKs.

API specification changes

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Improving Conversion Rates with Analytics, Design Principles, and UX

Rohini Pandhi — Tue, 29 Aug 2017 23:55:20 GMT

Co-Authors: Rohini Pandhi (Product), Jeremy Lubin (Design), Rajat Mittal (Engineering), Rachel Smith (Analytics)

Customer experience friction

We have big plans for Square Invoices, and we are constantly building new features to help our sellers easily send invoices and get paid fast.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using Word2Vec to Power a Recommendation Engine

Nicole Mitchell — Thu, 31 Aug 2017 17:12:47 GMT

About Us

Nicole is a rising junior at Rice University and Joy is a rising senior at University of Pennsylvania, and we are both software engineering interns at Square this summer. Square hosts an Intern Hack Week every summer, allowing interns the opportunit…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Tips and tricks for API pagination

Tristan Sokol — Thu, 07 Sep 2017 17:01:31 GMT

Welcome to the world of pagination — spreading out results over a number of pages or sections. I’ll provide an overview into some basic pagination concepts, and dive deep into how we do things at Square.

Introduction to pagination

The concept of pagination originally comes from books, but I think it’s easier to describe in terms of lists. You see pagination all the time on blogs, news sites, image sharing sites, etc. Whenever there isn’t enough room on the page to show all of…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Ember Run Loop and Asynchronous Testing

Ariel Jackson — Tue, 12 Sep 2017 22:10:18 GMT

This summer, I interned on the Square Seller Dashboard team, which works on the web application that Square merchants use for everything from checking sales, to managing their payroll, to signing up for Square Capital. For some context, I’m a rising senior at the University of Chicago and before this summer I’d never worked on a web application.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Transitioning from v1 Items to Catalog APIs

Tristan Sokol — Wed, 13 Sep 2017 18:09:33 GMT

Earlier this year, Square released new catalog endpoints to help manage your items in a more streamlined and scalable way. You might be familiar with the v1 endpoints create,retrieve, update and delete (CRUD) operations with items and their associated variations, modifier lists, modifier options, discounts, fees, etc. Catalog endpoints streamline all of these different entities into a single

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Autoscaling based on request queuing

Derek Hammer — Wed, 13 Sep 2017 21:37:36 GMT

Modern web development often includes traffic-heavy web applications and APIs. These services are tasked with a double-whammy: they need to be able to do a ton of work and to be able to do it for a significant number of requests. For example, a single application can be responsible for user authentication, request routing, view rendering (both HTML and JSON), business logic, and accessing data from a perm…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building for an omni-channel business with Square’s APIs has never been easier

Matan-Paul Shetrit — Thu, 14 Sep 2017 16:37:12 GMT

Starting with the launch of our E-Commerce API, we’ve worked to create a powerful commerce platform for both online-only and multi-channel businesses. In the last few months we’ve introduced our Catalog API, a tool to help businesses manage their products more efficiently, as well as

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Version 2.3.0 of our Client Libraries

Tristan Sokol — Fri, 22 Sep 2017 17:27:27 GMT

If you are familiar with How Square makes its SDKs then you know that one of the best ways to see what’s new in our latest SDK version is looking at the diff in our API specification on github (link).

Let’s dive into each change:

Orders Support

The largest update in this release is support for Orders endpoints. The new Orders endpoints allow you to create itemized transactions online, and are a big improvement in reporting for online sales. You can read more in the official announcement or jump right into the

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Apple Pay on the Web for Square’s APIs

Matan-Paul Shetrit — Wed, 27 Sep 2017 17:03:41 GMT

As many of you know, Square’s latest reader supports Apple Pay for payments made in-store. Today, we’re excited to announce that we are expanding our APIs to enable buyers to pay with Apple Pay on the web as well.

In the same way Apple Pay reduces lines and expedites checkout at a physical business, Apple Pay for web improves checkout speed and conversion online since buyers don’t have to enter credit card details and can authenticate the payment with Touch ID. With consumers increasingly making purchases on their mobile devices, we want to make it as easy and seamless as possible to provide that optimized…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Tips From a GHC Vet

Meghan McNeil — Thu, 28 Sep 2017 17:31:08 GMT

This will be my sixth year attending Grace Hopper. I have seen it grow from a small conference to over 10,000 employees. Square recently hosted a kick-off event where I talked through what I learned over the past couple of years. This post is meant …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A new partnership with Eventbrite, and the future of Square’s commerce platform

Carl Yates Perry — Thu, 28 Sep 2017 13:01:14 GMT

Today, we’re excited to share that we’ll be working closely with Eventbrite to ultimately provide their event creators with a single platform to accept online, mobile, and in-person payments using Square. These omni-channel payment capabilities will…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Let’s Encrypt & App Engine, pt. 2

Tristan Sokol — Fri, 29 Sep 2017 19:18:01 GMT

*For more background on using *Let’s Encrypt with *Google’s App Engine, read the original post *Setting up https for your website

When it came time to renew my Let’s Encrypt certificates for Google’s App Engine, I wanted to see whether I could improve the process. For my first attempt, I tried out the DNS verification method. I updated the appropriate TXT records for my domain, but either wasn’t able to do it correctly, or wasn’t patient enough for the caches to refresh fully, so I went back to good ol’ https verification instead. This ended up being a good choice when I decided to add more automati…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Helping merchants easily integrate online forms into their e-commerce site

Marylise Tauzia — Tue, 03 Oct 2017 18:27:01 GMT

A drag and drop form builder that was designed to let anyone — skilled developers to technophobes — create online forms in a few clicks.

Jotform started as a way for anyone to publish online forms that could take contact info and online applications. After building a strong base, JotForm realized that Square was a popular payment platform for their existing customers.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Using neural networks to predict customers’ needs

Ik-Hwan Kim — Thu, 05 Oct 2017 18:09:46 GMT

Square provides a powerful analytics tool called Seller Dashboard that gives our sellers insights into, and tracking of, their businesses. Using this tool, Square sellers can view their daily sales summary, manage inventory, confirm deposits, and do much more to untangle complicated tasks they face every day.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

See your location ID without the API call

Tristan Sokol — Wed, 11 Oct 2017 17:57:13 GMT

When merchants sign up for Square they create what we called a “location.” This location represents a distinct place that they do business. It could be a physical store, an e-commerce site, or even a mobile location like a food truck. These location…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Keeping the Daggers Sharp

P-Y Ricau — Wed, 11 Oct 2017 17:41:33 GMT

Favor constructor injection over field injection

Field injection requires the fields to be non final and non private.

// BAD
class CardConverter {

  @Inject PublicKeyManager publicKeyManager;

  @Inject public CardConverter() {}
}

Forgetting an @Inject on a field introduces a NullPointerException.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Listing your locations with Python

Tristan Sokol — Mon, 16 Oct 2017 16:54:41 GMT

Listing your locations programmatically can be important for managing applications for large companies or even multiple companies. Here is how you can get a list of your locations using our Python SDK.

Prepare

The first thing you’ll need to do is make sure that you have python working and install Square’s Python SDK. You can find the installation instructions here: https://github.com/square/connect-python-sdk#installation--usage

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Check out the new example in the sandbox section of Square’s developer docs

Tristan Sokol — Wed, 18 Oct 2017 21:06:35 GMT

From one point of view, applications built on top of Square’s APIs are just a series of API requests and code to display, store, or manipulate the data that gets returned. Wouldn’t it be interesting to see app in its simplest form — as an interactiv…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Product planning for machine learning

Juan Hernandez — Thu, 19 Oct 2017 17:46:52 GMT

By Juan Hernandez and Arthur Xu

When it comes to applied machine learning, the algorithm is often what captures the popular imagination. Most machine learning articles highlight the method to derive the model rather than the operating conditions needed to use the model successfull…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Creating a Customer in PHP

Tristan Sokol — Fri, 20 Oct 2017 21:24:46 GMT

You can’t have a business if you don’t have any customers, but importing customers from an existing system can be a pain, and sometimes you need to be able to do so programmatically. In PHP, our PHP SDK makes it fairly easy to create these customers using one simple script:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

What’s new in version 2.4.1 of our SDKs

Tristan Sokol — Tue, 24 Oct 2017 23:46:48 GMT

We’ve just released the latest iteration of our client libraries. Here’s what’s new from the 2.3.0 release:

**Support for Apple Pay. This **includes support for the associated data models and endpoints. You can read all about our Apple Pay web support in this blog post.
**SDK support for mobile locations. **Now the SDKs can return whether a location is a physical, brick-and-mortar storefront, or mobile, like a food truck.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A Fresh Update to our Platform Docs

Brian Gorby — Fri, 27 Oct 2017 20:03:52 GMT

Thoroughness, accuracy, and consistency are important tenets for any platform’s documentation. At Square we take our technical writing seriously and strive to ensure our documentation meets these tenets for our developers. But we also challenge ours…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Creating an employee with Python

Tristan Sokol — Fri, 27 Oct 2017 18:44:12 GMT

In this post we’ll go through the steps to create a new employee record attached to your Square business. If only actually hiring employees was as easy!

You’ll likely use this employee creation script as a part of some import or syncing script, but for this example we’ll make a standalone snippet that creates an employee.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How to add Masterpass support to your site

Matan-Paul Shetrit — Mon, 30 Oct 2017 18:17:30 GMT

As part of our continuous work to make it easier for our developers to support the growing range of online payment methods, we are happy to announce that now Square’s E-commerce API will support Masterpass for our U.S. sellers. By doing this we guarantee that our sellers will be able to close their sales with every method buyers are interested in paying with.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A new way for developers to monetize on Square’s platform

Matan-Paul Shetrit — Thu, 02 Nov 2017 17:26:55 GMT

Following our announcement in September that we’re working with Eventbrite to expand our offering for marketplaces, we’re excited to share that now marketplaces and platforms using our eCommerce API or Square Checkout can pay out their merchants and get paid themselves.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Adding card on file details with Python

Tristan Sokol — Wed, 08 Nov 2017 16:36:09 GMT

In this post we’ll be using the CustomerCard endpoints to add a card on file to a customer that you could then use for subscription billing online or in-person. But remember, you should not link a card on file to a customer without the customer’s express permission. For example, you can inclu…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

So You Have Some Clusters, Now What?

Inna Kaler — Thu, 09 Nov 2017 00:11:19 GMT

How to Add Value to Your Clusters

Written by Fan Zhang, Inna Kaler

Problem

One of the most common ways to apply unsupervised learning to a dataset is clustering, specifically centroid-based clustering. Clustering takes a mass of observations and separates them into distinct groups based on similarities.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

CreateCheckout options explained.

Tristan Sokol — Fri, 10 Nov 2017 16:43:43 GMT

We released Square Checkout as a way for developers to accept payments without having to deal with a card nonce or building a payment form user interface. In this post, we’ll dive deep on the different options available to you when generating a checkout form.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Updating from FactoryGirl to FactoryBot

David Haley — Tue, 14 Nov 2017 02:02:45 GMT

On October 24th, 2017 the ThoughtBot team renamed their popular Ruby testing library FactoryGirl to FactoryBot. They explained their reasoning:

Those who were bothered by the name shared a concern that female-gendered names (for software libraries and tools) in male-dominated spaces can be problematic. […] We concluded that, even though not everyone agreed, lack of concern from many shouldn…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

What’s new in version 2.5.0 of our client SDKs.

Tristan Sokol — Wed, 15 Nov 2017 22:11:37 GMT

Here’s a rundown of the changes:

Multi-Party transactions: This has been a big feature request from developers like you, as well as larger marketplaces and other platforms looking to integrate with Square. You can read more about this exciting release here: A new way for developers to monetize on Square’s platform

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A deep dive into authorization and delayed capture.

Tristan Sokol — Fri, 17 Nov 2017 20:20:19 GMT

Placing a hold on a card, or “pre-auth”-ing a transaction is very similar in practice as charging a card directly with the APIs.

When to delay capture?

Choosing to delay capture on a transaction instead of directly charging is usually decided by the type of business you have. You could place a hold on someone’s card while they borrow equipment or rent property. Other common use cases involve needin…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Version 2.5.1 of our Client SDKs

Tristan Sokol — Mon, 20 Nov 2017 20:42:23 GMT

We’re always working to expand our APIs and client libraries to give developers the tools they need to build their integrations with Square businesses. Here’s what’s new in our most recent version (2.5.1):

A new field (ordinal) was added to the CatalogItemVariation model. The ordinal is the order in which the item is displayed for the Square Point of Sale App.
The location model includes a field for website_url, which is the website that a merchant inputs when making their Square account.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Creating a personalized, professional ticketing experience for any business, powered by Square APIs

Marisa Almeida — Mon, 27 Nov 2017 19:48:32 GMT

Building a unique product

SimpleTix founder Aron Kansal first started tinkering with an event ticketing solution in college, over ten years ago. What began as a ticketing page he built in Adobe Dreamweaver for a small theater in Canada has now evolved into a flexible, full-s…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

OAuth with PHP, Part One: getting access tokens.

Tristan Sokol — Thu, 30 Nov 2017 18:22:04 GMT

This blog post contains information that is out of date and uses deprecated endpoints. Please visit migrating to refresh tokens for information on upgrading. To just implement the latest OAuth, you can follow our guide here.

OAuth is an important part in safely controlling access between developers’ applications and Square merchant accounts. If you are building your application for multiple Square accounts to use, you’ll need to implement it.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

OAuth with PHP Part Two: refreshing & revoking tokens

Tristan Sokol — Tue, 05 Dec 2017 17:27:29 GMT

This blog post contains information that is out of date and uses deprecated endpoints. Please visit migrating to refresh tokens for information on upgrading. To just implement the latest OAuth, you can follow our guide here.

This is a follow up to part 1 that talks about creating access tokens from authorization codes.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Storing customer card information securely using Point of Sale API.

Tristan Sokol — Wed, 13 Dec 2017 21:15:24 GMT

Turn on Card on File

You can enable Card on File right from the Square Point of Sale app:

Open the Square app and tap on the menu icon.
Tap Settings > Customer Management.
Toggle on Charge and Save Cards to Customer Profiles to save your customers’ payment card information from your in-app Customer Directory.
To save a card after a sale, toggle on Show Save Card Button After Checkout.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing the Square Connect Node SDK

Nisola Shobayo — Fri, 15 Dec 2017 22:22:18 GMT

As part of our goal of empowering our developers to innovate, build, and create, the developer platform team is happy to announce a new addition to the Square SDK family: the Square Connect Node SDK. With the release of the Square Connect Node SDK, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Topic Modeling

Alyssa Wisdom — Wed, 20 Dec 2017 22:38:24 GMT

Problem

Have you ever skimmed through a large amount of text and wanted to quickly understand the general trends, topics, or themes that it contains? This ranges from that book you never finished for book club to parsing through user feedback and comments a…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Accessible Colors for Data Visualization

Zach Grosser — Thu, 11 Jan 2018 00:01:35 GMT

A good graph is easy to read. A goal when creating data visualizations is to convey information in a clear and concise way. One of the most prominent features of most data visualizations is color, but what happens to a graph for someone who has diff…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Implementing Square’s Payment Form in Reaction Commerce

Richard Moot — Fri, 12 Jan 2018 00:59:44 GMT

Under the Payment Card Industry Data Security Standard (PCI-DSS), to process payments securely, you must minimize the amount of sensitive cardholder data that you handle. If you don’t, you could be vulnerable to a breach, lose your ability to process payments, or incur fines from your processor.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Soft-skills Reading List

Xavier Shay — Tue, 16 Jan 2018 19:56:11 GMT

As an engineering manager here at Square, I am often asked by engineers and other managers for advice on all sorts of different topics. If I’m lucky, they enjoy reading as much as I do, and I get the opportunity to recommend a book! Over the years, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Free Square plugin now available for WooCommerce

Marisa Almeida — Wed, 24 Jan 2018 17:30:14 GMT

WooCommerce integrated Square’s Transactions, Catalog, and Inventory APIs in one easy-to-install extension to make selling online and in-person simpler.

For developers who manage WordPress or WooCommerce sites for clients: we wanted to make sure you saw that the Square extension for WooCommerce is now available to install for free. This has been a top request from sellers and developers alike, and we’re excited it’s now a reality.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Caviar’s Word2Vec Tagging For Menu Item Recommendations

Christopher Skeels — Mon, 29 Jan 2018 19:41:15 GMT

Background

Recommendation Collections

At Caviar, Square’s food ordering app, one way we connect diners to great food is with restaurant and menu item recommendations. Rather than presenting a single overwhelming stream of recommendations, we segment them into distinct recommendation collections, each characterized by a common theme (e.g., “Delivery Under 30 Minutes”, “Pizza”, and “Recommended For You”). Individ…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Getting Started Exploring SDKs with REPL-Driven Development in Node.js,

Shannon Skipper — Tue, 30 Jan 2018 23:08:26 GMT

The faster it is to get up and running with an API the better. SDKs help speed up that on-boarding process by providing an already-written, pre-made API client that just works in the language you’re already using. The Square Connect API, for example, has SDKs in half a dozen languages.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Lightning Talks: Let’s build a Markdown parser!

Square Engineering — Tue, 30 Jan 2018 18:23:33 GMT

Every month, Square Engineers give lightning talks internally. We’re excited to share some of our favorites!

Enjoy this lightning talk where Winnie Wu explored how her team built a markdown parser in their Ruby on Rails app.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Stop Using Servers to Handle Webhooks

Richard Moot — Mon, 05 Feb 2018 18:01:02 GMT

Webhooks are increasingly becoming the main method to get real time data from different services. GitHub, Slack, SendGrid, and even Square use webhooks to let you see data or be notified of events happening on your account. Webhooks are awesome, since they are fairly easy to deal with and prevent developers from having to build some archaic polling system that ends up being fairly wast…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Uncovering Inconsistent Keychain Behavior

Kevin Leong — Thu, 22 Feb 2018 16:55:59 GMT

A few months ago, a developer sent the following error stack trace to Square from their iOS app:

2017-08-07 21:41:37.458 [**App name redacted**][5316:2314238] *** 
Terminating app due to uncaught exception 'NSInvalidArgumentException', 
reason: '-[__NSCFData isEqualToString:]: unrecognized selector sent to instance 0x6080000b97b0'

*** First th…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Deep Learning + Survival Analysis: Our Approach to Multi-Task Frameworks

Stephane Fotso — Mon, 26 Feb 2018 22:00:52 GMT

At Square, we’ve experimented with survival analysis models to predict a variety of outcomes: from Seller churn and product conversions, to loan defaults on Capital. Predicting these key events in a seller’s lifetime allow us to provide a better use…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

You Are Your Own Best Hype Person

Marie Chatfield — Mon, 26 Feb 2018 20:36:46 GMT

At some point in your career, you’re going to have to prove to someone that you’re worth it: worth hiring, worth promoting, worth the raise, worth taking a risk on. If you’re lucky, you might have someone who has seen your work first hand, who belie…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Lightning Talks: How to Create and Deliver a Successful Tech Talk

P-Y Ricau — Tue, 27 Feb 2018 18:06:38 GMT

Every month, Square Engineers give lightning talks internally. We just started sharing some of our favorites.

Over the last two years, I’ve provided speakers with early feedback on their technical presentations. Eventually, it made sense to compile these tips into their own lightning talk. Here are some pointers on how to create a successful tech talk that …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Understanding Composition Browser Events

Jeff Lloyd — Thu, 01 Mar 2018 22:48:02 GMT

Our Square sellers need a consolidated view of their whole business — that’s where Dashboard comes in. Dashboard is a large frontend Ember application that enables sellers to run their business effectively through analytics, reporting, and various s…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

How To Be a More Influential Engineer

Derek Hammer — Wed, 07 Mar 2018 22:03:12 GMT

One of the most significant transitions for an engineer’s career is when they break dependence on senior team members and start to actively contribute to the team’s decision-making process. Once this transition is complete, the engineer is contribut…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Product Analytics at Square

Fan Zhang — Mon, 12 Mar 2018 23:25:35 GMT

Product Analysts at Square leverage engineering, analytics, and machine learning to empower data-driven decision making in the full lifecycle of product development. We lead experimentation and growth initiatives, develop automation solutions to per…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

OAuth, wherefore art thou?

Richard Moot — Tue, 20 Mar 2018 16:19:34 GMT

Shakespeare’s plays are wonderful expressions of beauty and romance. His plays are also complicated, tragic, and hard to understand. Working with OAuth can feel a lot like Shakespeare. It sounds overly complicated, but the more time you spend with i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ember and Yarn Workspaces

Lenny Burdette — Wed, 28 Mar 2018 20:04:58 GMT

Square Dashboard circa 2012 versus Square Dashboard in the near future

Building so much functionality into a single application allowed us to move quickly with new products and bug fixes. Until late last year, we didn’t have another option—we were using a bespoke Rails-based build pipeline that didn’t understand Ember …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Making AI Interpretable with Generative Adversarial Networks

Juan Hernandez — Wed, 04 Apr 2018 16:48:24 GMT

Authors: Juan Hernandez | @damienrj

AI has made tremendous advances in technology, business, and science in the past decades, and this progress continues to accelerate today. Many of our experiences in daily life are influenced by AI and machine learning. For example, music is recomme…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Lightning Talks: A Tour of Duty at the U.S. Digital Service

Square Engineering — Thu, 12 Apr 2018 21:20:12 GMT

Every month, Square Engineers give lightning talks internally. We’re excited to share some of our favorites!

Zach talks about working with the USDS, some of their core values, and his work on login.gov. In learning about the values of the USDS, we can see how the government aims to better serve people in the future as we become more reliant upon the internet and digital services.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Documentation Details Matter

Alex Jacque — Thu, 12 Apr 2018 12:01:01 GMT

Not too long ago I joined the Developer Platform team at Square as a product designer. One of the first things I was tasked with was addressing some quick-hit, tactical improvements we could make to our existing site to improve the developer experience.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Super Simple Serverless eCommerce

Richard Moot — Thu, 19 Apr 2018 18:22:08 GMT

A lot of companies have been taking the plunge into utilizing serverless eCommerce in order to enhance their tech stacks (e.g., Nordstrom, Netflix, and Coca-Cola). It may seem like serverless is just a growing fad, but that was the same line of thought many people had about

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ruby’s New Infinite Range Syntax: (0..)

Shannon Skipper — Fri, 20 Apr 2018 01:54:08 GMT

Introducing Ruby 2.6’s Endless Range

On Christmas Day, 2018, Ruby 2.6 will be released with support for a new syntax denoting an endless range:

42..
#=> 42..nil # yes, this is infinite!

So why do we need this new syntax? Up to this point, it has been a bit clunky in Ruby to create an infinite range:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Migrating to Warmer Times Ahead

Robbin Xu — Mon, 23 Apr 2018 23:26:02 GMT

Caviar’s consumer web frontend architecture has changed a lot over the years. It was built as one large Rails application with Slim used as the templating engine, and jQuery and CoffeeScript added to handle client-side logic. They were the tools most familiar to the people who used them at that time.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

New Class Naming Rules in Ruby

Shannon Skipper — Thu, 03 May 2018 17:23:23 GMT

In Ruby 2.5 and prior:

It’s been a longstanding rule in Ruby that you must use a capital ASCII letter as the first character of a Class or Module name. This limited you to just these 26 characters:

ABCDEFGHIJKLMNOPQRSTUVWXYZ

New in Ruby 2.6:

In Ruby 2.6, non-ASCII upper case characters are allowed. By my count, that makes a total of 1,853 options! Here are the 1,827 new characters that can start a Class or Module name in Ruby 2.6:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Ruby’s New Exception Keyword Arguments

Shannon Skipper — Tue, 15 May 2018 14:00:56 GMT

In Ruby 2.6, a variety of Kernel methods get a new exception: false or exception: true keyword argument. When Kernel methods fail, some raise an error and some just return nil. This new feature lets you override that default behavior.

TL;DR: In Ruby 2.6 these examples will all work:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Creating a Chatbot with Square Checkout and Twilio Studio

Tristan Sokol — Thu, 17 May 2018 19:28:33 GMT

Try it out! Text (479)-888–5188 to talk to the bot 📲

From voice commands to chatbots, consumers are engaging with (and buying) things in totally new ways. But this isn’t something only for multi-billion dollar tech companies. New tools make chatbots achievable for even the smallest developer, so anyon…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Are hotdogs a sandwich?

Derek Hammer — Thu, 24 May 2018 17:11:43 GMT

There is an ongoing, raging debate at Caviar about sandwiches, hot dogs, and all manner of food. As you can image, as a food company we encounter all kinds of fun, quirky takes on food and as a result we get ourselves into a ye olde semantic debates…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

measureBlock: How Does Performance Testing Work In iOS?

Thomas Lextrait — Tue, 29 May 2018 23:05:34 GMT

I was working on a mini project at Square involving performance unit testing for iOS — essentially, looking into how we could introduce performance unit testing, what our options are, and how it would scale on our CI (continuous integration). In focusing on the one tool Apple provides as p…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Design your custom payment form with SqPaymentForm

Stephen Josey — Tue, 29 May 2018 16:58:10 GMT

Do you currently use the SqPaymentForm, but you want it to look sleek and professional? Now is your chance to figure out how to make it look like anything you want! Let’s get started.

An aside: I assume that you have at least looked over the SqPaymentForm Overview page on Square’s doc site. If not, please do so now, because this article will refer to items from the doc site.*

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Four Steps to use Sketch Libraries Efficiently

Josef Khoo — Mon, 04 Jun 2018 07:58:45 GMT

What is the height of a button?

Where do I find this calendar?

When was the gray updated?

Why is the heading size inconsistent?

For a long time, sharing UI libraries and systems was a very manual process that often crumbled under the effort to maintain and keep everything updated. A stale style guide was very common; every time a new one was created, everyone would once agai…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Taking Payments Online with Square and Vue.js

Tristan Sokol — Tue, 05 Jun 2018 14:06:01 GMT

Vue.js is a popular choice when it comes to front-end JavaScript frameworks. It has handy features like data binding and easy rendering control out of the box, all while having the performance and extensibility you need. But what if you want to take some …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Caviar’s Food Recommendation Platform

Christopher Skeels — Wed, 13 Jun 2018 23:26:23 GMT

Intro

At Caviar, Square’s food ordering app, one way we connect diners with great food is our home feed of recommendations. We have a large variety of recommendations to make, and we want to constantly test and evaluate them. To support this, we’ve created a flexible, powerful recommendation…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Challenge — Table of Contents Generator

Brandon Weaver — Tue, 19 Jun 2018 19:56:38 GMT

While solutions are present later in the article, we encourage you to give the challenge a try first! We’ll be highlighting the top solutions we get over on Twitter at @SquareDev.

The Problem

Questions questions, we’ve got a question.

Given an HTML page with multiple headers, we want to extract the headers to make a table of contents:

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Keeping API Errors Clean

Derek Hammer — Mon, 25 Jun 2018 17:57:22 GMT

At Caviar, we build a good number of APIs. We build APIs for our internal service-to-service communication, APIs for our mobile apps to consume, APIs for our web apps to consume, APIs for external partners, and probably a couple of APIs that I’m eve…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing cocoapods-generate

Samuel E. Giddins — Mon, 25 Jun 2018 18:00:56 GMT

Here at Square, we use CocoaPods as a core part of our iOS development workflow, with extensive libraries within the Square Point of Sale app alone, in addition to libraries used within our test suites. Many of these libraries live inside our main i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Serverless Instant Checkout Links with Square

Richard Moot — Tue, 26 Jun 2018 17:11:12 GMT

Servers beware! Watch out containers! Our serverless overlords are here! There is a lot of hype around serverless and talk about it being the end of containers, but we’re still not seeing a whole lot of major adoption of the technology (at least not…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Connect 2.8.0 SDKs

Richard Moot — Thu, 05 Jul 2018 17:36:00 GMT

We’ve got some new and useful features with the latest version of our SDKs. If you haven’t already implemented, you’re in luck, and if you already have, read on about the cool new features you can get by upgrading.

What’s in this release

We added sorting functionality to the Connect v2 Customer API
Updated the Connect v1 Payments API to include information about surcharges
Made improvements to the Item data type.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

API Versioning for Connect v2

Richard Moot — Fri, 13 Jul 2018 16:59:14 GMT

We’ve got an exciting update coming for our Connect v2 developers! We have released versioning for all Connect v2 endpoints for Square’s APIs. This will allow us to deliver more functionality and features faster than ever before. No need to worry though, our APIs will remain backwards-compatible and will allow you to upgrade when you’re most comfortable. This means you …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

LeakCanary 1.6 🐤

P-Y Ricau — Tue, 24 Jul 2018 18:00:58 GMT

We just released a new version of LeakCanary, and it’s got several new features!

dependencies {
  debugImplementation 'com.squareup.leakcanary:leakcanary-android:1.6.1'
  releaseImplementation 'com.squareup.leakcanary:leakcanary-android-no-op:1.6.1'
  // Optional, if you use support library fragments:
  debugImplementation 'com.…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Women Who Make

Jackie Luo — Thu, 26 Jul 2018 19:44:31 GMT

This month is WomEng Spotlight Month at Square, and so we took it as a time to celebrate women engineers—in the company and outside of it. We organized a Square seller pop-up at our office, featuring women engineers and designers… who happen to be m…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square WomEng Hear + Now 2018: Lightning Talks

Square Engineering — Wed, 01 Aug 2018 20:49:04 GMT

Hear + Now is a tech lightning talk series hosted by Square’s WomEng organization. The purpose of Hear + Now is to amplify the voices of people from marginalized groups within the tech industry.

This year’s topic was “The Struggle,” with speakers sharing their technical struggles, workplace struggles, and more.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Square Reader SDK

Gabriel Jinich — Thu, 02 Aug 2018 17:00:19 GMT

It’s been two years since we introduced Square Developer, our platform that empowers developers to build custom solutions for Square sellers. Since then, developers have used Point of Sale API to build custom solutions used by thousands of sellers, leveraging Square hardware.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Spiking Out a GUI Employee Time Clock

Shannon Skipper — Wed, 08 Aug 2018 17:51:14 GMT

As small companies get bigger, they sometimes decide to start using time clocks to track employee hours. Stakeholders often ask engineering for a solution that’s easy to use. As Rubyists, we usually create command line apps or web apps, but sometime…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Comparing Two Forward Feature Selection Algorithms

Patrick Callier — Wed, 08 Aug 2018 21:52:26 GMT

I. Introduction

In this post, we review some things we learned from our first experiments on production feature selection applications. We focus on two variants of stepwise selection: (1) The linear stepwise selection method of Efroymson [2], herein known as *linear *forward stepwise, and (2) a custom logistic regression stepwise selection method using two passes through the data that we dub

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Risky Business: Interning on Square’s Risk Team

Tatiana Doyle — Fri, 10 Aug 2018 22:58:32 GMT

Square’s main purpose is economic empowerment. Most people associate the company most strongly with its credit card processing product, the iconic Square Reader.

Square’s credit card reader

Allowing small businesses to accept credit cards has enabled them to grow their businesses in an era where everything is going digital. Today, I can tap my phone to buy groceries without ever pulling out a physical card. However, credit cards are an…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Keeping Your Customers up to date.

Tristan Sokol — Thu, 16 Aug 2018 17:31:00 GMT

Square customer management can usually meet all your needs, but at times you might need to keep your customer directory in sync with another customer database or order management system. Luckily some new changes to our APIs make that easier than eve…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Connect SDKs: Instant Profiles & Search Customers

Richard Moot — Fri, 24 Aug 2018 18:07:43 GMT

The release of version 2.9.0 (now 2.20180712.1, with the release of API versioning) of the Square SDKs brought some really cool functionality along with it.

You now get access to all of your customer profiles via the Customers API. Before, you could only retrieve customer profiles that you’d created using the API, but now you can also see Instant Profiles as well.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Okio 2

Jesse Wilson — Mon, 27 Aug 2018 18:51:38 GMT

At Square, we’re excited about Kotlin. It’s a capable language to build Java libraries and applications with. We love to write code that is both compact and efficient.

We’re also eager to adopt Kotlin’s powerful new features. Kotlin/Native will allow us to share code between iOS and Android. Coroutines make concurrent programs easier to create and maintain.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

A silent meeting is worth a thousand words

P-Y Ricau — Tue, 04 Sep 2018 18:51:01 GMT

Picture this: a room full of senior Square leads, gathered for an important review meeting. Everyone is looking at their computer, in complete silence, interrupted by bursts of clickety clack. 30 minutes later, the conversation starts.

What is going on? Is everyone waiting for the meeting to start? Are they practicing some form of silent retreat microdosing?

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Women Who Make (Part 2)

Ken Sin — Thu, 06 Sep 2018 21:18:30 GMT

At Square, each of our community groups has a spotlight month. WomEng Spotlight Month at Square ran through July, celebrating women engineers both inside Square and outside. We organized a Square seller pop-up at the SF office, which we covered in P…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Building a photo booth for Droidcon NYC

P-Y Ricau — Fri, 07 Sep 2018 00:52:10 GMT

A month ago, my team at Square released the Reader SDK. We had the opportunity to show a demo at Droidcon NYC. How could we make payments cool?

We set up to build SquickPic, a fun Android photo booth: pay a dollar 💳, choose a filter, smile, Snap! 📸 The photo booth prints the picture and tweets it 🐦 (@SquickPic).

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing Square Connect v2 Inventory API

Lior Koren — Tue, 18 Sep 2018 17:39:00 GMT

We are very pleased to announce the release of Inventory API to Connect v2. With this release, we’ve significantly upgraded functionality for the Inventory API. If you haven’t implemented the Connect v1 Inventory API, you’re coming in at the right t…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Google Pay in Square Online Payments APIs and Square Invoices

Ajay Anandan — Fri, 21 Sep 2018 17:23:50 GMT

Today, we are delighted to announce that Square online payments APIs and Square Invoices now support Google Pay. This new integration allows developers and sellers to enable a fast and frictionless checkout experience on their websites or online sto…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square implementation with Laravel

Nikola Gavrić — Mon, 24 Sep 2018 16:41:47 GMT

Background and introduction

Hello! I’m Nikola Gavrić, a Software Engineer in Niš, Serbia. I was using Square for several projects and after searching to find a library for the Laravel framework (there were basically no Square integrations with Laravel), I decided to create my own. After receiving emails from developers requesting various features, I decided to make Laravel Square developer-friendly and easy-to-use with low-effort required…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Reader SDK for React Native

Richard Moot — Thu, 27 Sep 2018 17:27:33 GMT

In the beginning of August, we announced the release of our Reader SDK for iOS and Android to allow developers to build their own custom in-person payment experiences.

Now, we’ve taken that ground-breaking SDK and wrapped it up in a React Native plugin that you can use in your own React Native project. So whether you’re a cross-platform guru looking to creating the ultimate in-person payment experience or just a R…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Useful tools: Headless Chrome & puppeteer for browser automation & testing.

Tristan Sokol — Thu, 11 Oct 2018 19:06:26 GMT

Websites have become more complicated than ever. Instead of a single html page, modern sites are often composed of multiple component files that are packaged together and then optimized. When a site loads these files, it makes dozens of different as…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

SqR00t Offensive Security Tech Talks

Flee — Mon, 15 Oct 2018 17:37:20 GMT

Square’s Information Security team runs a quarterly security meetup, Square R00t, which features several security- and data privacy-related lightning talks.

Recently, Jason Haddix, Chris Rohlf, Jake Heath, and Michael Roberts gave infosec talks at our “Square SqR00t — Offensive Security” event in Square’s San Francisco office. (Thanks to everyone who attended!) Two of these talks were recorded and are n…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Women of Bitcoin

Square Engineering — Wed, 17 Oct 2018 17:19:46 GMT

In the first edition of our “Women of BTC” series, we’ll talk with two influential Cash App team members: **Liang Shi **on the Marketing team and **Rebecca Corcillo **on Engineering.

Liang has been at Square just about a year and is already making a massive impact on the experiential marketing front. Before she came to Square, Liang was organizing design and experiential events, including a dessert festival in NYC and LA.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Open Sourcing Subzero

Alok Menghrajani — Tue, 23 Oct 2018 01:12:46 GMT

Late last year, Square began offering the ability to buy and sell Bitcoin with Cash App. As part of that launch we invested heavily in building out our cryptocurrency infrastructure to help protect our customers’ funds, and Square itself, from both internal and external threats.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Women of Bitcoin: Volume 2

Square Engineering — Wed, 24 Oct 2018 21:24:26 GMT

In the second edition of our “Women of BTC” series, we talked to members of the Finance and Legal departments: Emily Pirnack and Crissy Solh.

Emily is part of Square’s Finance & Analytics group’s Treasury team. She joined two years ago from Hitachi where she worked on FX trading. When the Cash App team first started building Bitcoin functionality, they needed someone to lead the trading i…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Top 10 things I learnt coding on the side

Liching Li — Sun, 28 Oct 2018 07:44:38 GMT

Liching is a machine learning engineer on the Cash App team in Square’s Melbourne office working on risk and fraud detection. She is new to machine learning, but loves coding on the side and has learnt some really valuable lessons she’d like to shar…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Enabling Modern JavaScript in Rails with Webpack(er)

Tingshen Chen — Tue, 06 Nov 2018 02:33:27 GMT

When I joined Caviar in 2016, I was fully bought into React and all the good stuff around building modular systems. jQuery was no longer the cool kid around the block. NPM was the place to go to get any missing dependencies. ES6 was starting to gain…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Sharding Cash

Jon Tirsen — Wed, 07 Nov 2018 19:19:54 GMT

As we approach the end of 2018, we’re celebrating the anniversary of the first shard split for Cash App with a series of blog posts explaining how we used Vitess to scale out. Rapid growth is hard, and it’s not always a smooth ride. We’re excited to…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Inferring Label Hierarchies with hLDA

Wafa Soofi — Wed, 14 Nov 2018 01:34:48 GMT

The Problem: Organizing Square Support Center Articles

At Square, we get businesses up and running quickly. We also work hard to make sure sellers get their questions answered quickly. When Square sellers encounter a problem with a Square product, one of the first lines of defense is Square’s Support Ce…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Exploring Ruby 2.6 — Enumerator, Hash, and Enumerable Changes

Brandon Weaver — Wed, 14 Nov 2018 00:49:34 GMT

As we get closer to Christmas, we’re going to see more and more features for Ruby 2.6. Some of them haven’t been discussed much, including Enumerable and Enumerator, and I’ve found those changes particularly interesting. Let’s take a look.

Christmas is coming, and with it some fun new presents in Ruby!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Combining Behavior and E-mail Content to Improve Customer Support

Stephane Fotso — Wed, 14 Nov 2018 22:37:11 GMT

Introduction

One of our primary objectives at Square is to provide exceptional customer experience, especially when the customers are entrusting the company with their financing. This is even more critical for us at Square Capital, the lending arm of Square, where our sellers are also borrowers. Our operations team is devoted to this goal and provides consistent, fast and tailored responses to seller inquiries regarding loan products. Every year, the team receives tens of thousands of emails from se…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Remodeling Cash App Payments

Jesse Wilson — Fri, 16 Nov 2018 18:24:08 GMT

Before we could partition our database we needed to prepare our data model. Here’s how we turned a simple normalized data model into one that could be partitioned for scale.

Normalized Data is Beautiful

The Cash App started as a simple service for sending money. Our MySQL database tracked customers, their linked debit cards, and the payments between them.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

K-Means for Building Better Product Experiences

Andrew Currie — Tue, 20 Nov 2018 23:15:27 GMT

As the team continued to iterate on and improve Square for Retail, we wanted to understand behaviors that led some sellers to convert from a free trial to a paid subscription. We also wanted to understand how they use some of Square for Retail’s key…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Women of Bitcoin: Volume 3

Square Engineering — Tue, 27 Nov 2018 22:17:30 GMT

Tobi has been at Square for just over two years, after joining us from Microsoft, and is a key member of our server engineering team. She works specifically with the Cash balance and Cash Card workstreams, but pinch hits across Cash App’s various en…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Online Payments with React + Square

Richard Moot — Tue, 27 Nov 2018 22:41:49 GMT

The info found here is now out of date, as SqPaymentForm has been replaced with Web Payments SDK. Check out our updated blog post!

There are a lot of ways to accept payments online. Wouldn’t it be nice to implement a single form that could accept as many payment methods as we want at a single time? Let’s take a look at implementing a custom payment form using Square and React. This form will enable us to take credit cards online,

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Abstracting Sharding with Vitess and Distributed Deadlocks

Mike Gershunovsky — Tue, 27 Nov 2018 19:32:05 GMT

One of the main reasons Vitess was such a success for Cash App is that it abstracts database sharding away from the application code. This allowed us to shard our database without rewriting thousands of transactions in our application.

When the application issues write operations on two entity groups that are on different shards, Vitess will automatically open transactions on all shards that are necessary to complete the operation.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Reliable Webhooks Using Serverless Architecture

Victor Zhu — Tue, 27 Nov 2018 22:30:32 GMT

For those who are already Square Developers, you probably already heard our announcement of webhooks being more reliable. If you haven’t: in October, we released more robust and reliable webhooks to better serve events to developer’s applications. Today, we’re sharing how we achieved that.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Cross-Shard Queries & Lookup Tables

Aaron Young — Tue, 04 Dec 2018 18:13:08 GMT

Sharding Cash’s database with Vitess was a massive undertaking that set us up for the future, but it was just the start of the journey. The sheer rate of growth of our traffic necessitated a focus on splitting the data to multiple machines as quickly as possible. Migrating from a traditional database to a dist…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square + Flutter: Beautiful, fast mobile payment apps

Shannon Skipper — Tue, 04 Dec 2018 17:20:19 GMT

Flutter is Google’s new framework for building beautiful native apps on iOS and Android from a single codebase. Today, we’re excited to announce that Square and Flutter have partnered to create plugins to take in-app and in-person payments from Flutter apps!

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Build a digital wallet only checkout to boost online sales.

Ajay Anandan — Wed, 05 Dec 2018 22:24:30 GMT

Cyber Monday 2018, the busiest day for online shopping, hit new highs in 2018 with $7.9 billion in sales. Mobile devices (phones and tablets) accounted for more than 57% of the traffic but only for 39% of the sales. This is because conversion rates are typically lower on mobile devices compared to desktops.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

KotlinPoet 1.0 is here!

Egor Andreevich — Fri, 14 Dec 2018 21:19:41 GMT

KotlinPoet is a collection of Kotlin API that makes generating .kt files easy. It’s inspired by JavaPoet, a Java code generation library, which powers a number of widely used frameworks, such as Dagger.

KotlinPoet has been around for over a year and is used by a number of popular libraries, such as Moshi and SQLDelight. It’s sweet, it’s battle-tested, it’s ready for prime-time, and today we’re announcing KotlinPoet 1.0! 🎉

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Scaling Christmas — An Illustrated Adventure

Brandon Weaver — Tue, 18 Dec 2018 00:42:23 GMT

The lemurs are back! This time they’ve come for a special Christmas-themed adventure about how Christmas scales, using practical lessons in holiday operations.

Now let’s see what they’re up to today.

Meet Red

You may have already met Red some time in the past from other talks and events. For those of you who haven’t had the pleasure, Red is a magical lemur. He’s also particularly fond of Christmas, especially presents.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Operating Vitess

Michael Pawliszyn — Tue, 18 Dec 2018 19:00:32 GMT

It has been quite the challenge bringing Vitess online over our existing MySQL database, then sharding and operating it at greater scale over time. Individuals love using the Cash App, and while that is a great thing, being unprepared for peak load …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Making the Invisible Visible: A Look at Building Tools for Square Developers

Lindy Zeng — Wed, 09 Jan 2019 01:23:07 GMT

At Square, the Developers team exposes APIs that allow third-party developers to build custom business-processing solutions. On October 18, we announced to developers using our APIs that webhooks would now support retries. If a webhook cannot be del…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Announcing SQLDelight 1.0

Alec Strong — Tue, 08 Jan 2019 19:21:46 GMT

SQLDelight started as a project 4 years ago on the ContentValues and SQLiteOpenHelper APIs from Android with the goal of making writing SQL easy and safe. The library was an early adopter of Kotlin internally, but has been generating Java since its …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Introducing Square In-App Payments SDK

Ajay Anandan — Wed, 09 Jan 2019 17:00:07 GMT

It’s no surprise that mobile commerce continues to gain popularity. For example, in 2018, mobile accounted for 66% of sales during Black Friday and Cyber Monday. As we’ve built out the Square developer platform over the past few years, our developer community has been asking for the ability to take payments through Square natively within their mobile app running on a bu…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Understanding the Essentials: Idempotency

Tristan Sokol — Thu, 24 Jan 2019 19:08:32 GMT

As a developer, you are always wanting things to go smoothly, but in the world of REST APIs, that isn’t always the case. Client failures, networking errors, or just poorly written code can all spell trouble for an API call (and your end user experie…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square Elected to a Third Term on the PCI SSC’s Board of Advisors

Shane Bauer — Fri, 25 Jan 2019 20:03:44 GMT

We’re excited to share that Square has been elected to a third term on the Payment Card Industry Security Standards Council’s board of advisors.

The Payment Card Industry Security Standards Council (PCI SSC) leads a global, cross-industry effort to increase payment security by providing industry-driven, flexible and effective data security standards and programs that help businesses detect, …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

OkHttp 3.13 Requires Android 5+

Jesse Wilson — Tue, 05 Feb 2019 16:50:59 GMT

Today we’re releasing OkHttp 3.13. With this update we’re bumping the project’s requirements from this:

Android 2.3+ / API 9+ (released December 2010)
Java 7+ (released July 2011)

to this:

Android 5.0+ / API 21+ (released November 2014)
Java 8+ (released March 2014)

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Store a Card on File using Reader SDK

Gabriel Jinich — Wed, 13 Feb 2019 19:00:13 GMT

Last year, we announced the release of Square Reader SDK for iOS and Android, along with plugins for React Native and Flutter. While Reader SDK makes it easy to take in-person payments within your own app using Square hardware, you may also want to store customer card information securely to use in the future (for example, to create a recurring billing plan).

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Orders Push Beta

Chris Wiggins — Wed, 13 Feb 2019 22:08:55 GMT

Buyers are everywhere. And I really do mean everywhere. They’re purchasing on websites, web apps, native mobile apps, and even in messaging apps. There has been an explosion of places where buyers are making these purchases, and we’re here to connec…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Engineering Management Philosophies and Why They Matter Even if You Are Not a Manager

Annie Zhou — Tue, 12 Mar 2019 21:23:57 GMT

Annie is a software engineering manager leading a platform team within Square’s platform & infrastructure engineering organization. Prior to Square, she worked at a number of startups across a spectrum of industries from consumer products to enterpr…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

What you need to know about Strong Customer Authentication (SCA)

Richard Moot — Thu, 14 Mar 2019 12:00:00 GMT

Last updated on December 23, 2020

What is SCA?

Strong Customer Authentication (SCA) is a new European requirement to make online and in-person payments more secure in the European Economic Area (EEA).

Currently, when paying online, customers need to enter their card number, expiry, CVV, and postal code to make a payment. When SCA enforcement begins, customers will be required to complete two of the three factors of authentication when initiating …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Square In-App Payments SDK for React Native

Richard Moot — Fri, 15 Mar 2019 16:36:30 GMT

Since the release of our In-App Payments SDK, we’ve been getting a lot of requests for when this would be available for React Native. It is officially here! You can simply npm install — save react-native-square-in-app-payments inside your React Native project and follow the setup guide over

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Streamline Checkout with Shipping Options in Apple Pay

Ajay Anandan — Thu, 28 Mar 2019 18:12:50 GMT

A little over a year ago, we added support for Apple Pay on the Web in our Online Payments APIs to help developers easily integrate Apple Pay into their websites. However, we know eCommerce checkouts don’t stop with payments — you also need to colle…

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

Mobile Web Performance @ Caviar

Evelyn Chan — Thu, 28 Mar 2019 22:46:48 GMT

Across any e-commerce website, page load times are directly correlated with conversion rate. Faced with a page that takes longer than 3 seconds to load, 53% of users drop off, perhaps never to return. A 1 second delay in load time results in a 7% loss in conversions, 11% fewer page views, and 16% decrease in customer satisfaction.

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)

The Road to an Envoy Service Mesh

Snow Pettersen — Fri, 29 Mar 2019 15:36:51 GMT

At Square we’ve been running a microservices architecture for years, primarily using three different languages: Java, Ruby and Go. Running such a diverse stack can make interoperability between the different languages/frameworks challenging, and in …

(This is an article posted at https://developer.squareup.com/blog/. You can read it online by clicking here.)