RxJava
RxJava – Reactive Extensions for the JVM – a library for composing asynchronous and event-based programs using observable sequences for the Java VM. (by ReactiveX)
Vert.x
Vert.x is a tool-kit for building reactive applications on the JVM (by eclipse-vertx)
| RxJava | Vert.x | |
|---|---|---|
| 18 | 52 | |
| 48,239 | 14,671 | |
| -0.1% | 0.1% | |
| 9.2 | 9.7 | |
| 7 days ago | 7 days ago | |
| Java | Java | |
| Apache License 2.0 | GNU General Public License v3.0 or later |
The number of mentions indicates the total number of mentions that we've tracked plus the number of user suggested alternatives.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
Stars - the number of stars that a project has on GitHub. Growth - month over month growth in stars.
Activity is a relative number indicating how actively a project is being developed. Recent commits have higher weight than older ones.
For example, an activity of 9.0 indicates that a project is amongst the top 10% of the most actively developed projects that we are tracking.
RxJava
Posts with mentions or reviews of RxJava.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2026-02-10.
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Mastering Reactive Programming in Modern Mobile Development
RxJava Documentation
- Why Ruby's Timeout is dangerous (and Thread.raise is terrifying) (2015)
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Top 10 GitHub Repositories for Python and Java Developers
3. RxJava This repository contains the source code for ReactiveX, a library used to create asynchronous and event-based programs with observable sequences. https://github.com/ReactiveX/RxJava
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Humble Chronicles: Managing State with Signals
Is this similar RxJava, the reactive extensions library for https://github.com/ReactiveX/RxJava ? I have made that work in Clojure in production.
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How to do threading in Android.
Since you mentioned java, there is RxJava and RxAndroid. Google general recommendation now is to use kotlin coroutines if you're considering writing your app with that.
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It hurts
It's very quick though. In terms of the correctness of the syntax, I've never seen an issue while translating a single file or a single function. When I took the entire RxJava code base 5 years ago, right clicked on the source folder and converted to Kotlin, I found lots of problems. File by file I've never seen any issues though, but I also haven't done it much.
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must known frameworks/libs/tech, every senior java developer must know(?)
You all beat me to MapStruct and Testcontainers. Honorable mention to RxJava, which I use in Desktop apps.
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What is your tech stack?
RxJava with RxRelay (and rx-combinetuple-kt)
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Best libraries for Android Developers
RxJava2
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Reactive Data Streams - quick rxJava Summary
More information about rxJava, check it out here: (HERE)[https://github.com/ReactiveX/RxJava]
Vert.x
Posts with mentions or reviews of Vert.x.
We have used some of these posts to build our list of alternatives
and similar projects. The last one was on 2026-05-21.
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Standing on shoulders: the stack that makes Floci start in ~24ms
Vert.x is the layer where Floci uses things directly. It's Netty with ergonomics: an event loop, a router, protocol-specific APIs for HTTP, DNS, TCP, WebSockets, gRPC, all sharing the same threading model.
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What kind of ORM engine does a low-code platform need? (2)
Traditionally, JDBC interfaces are all synchronous, so JdbcTemplate and HibernateTemplate are also synchronous. But as asynchronous high-concurrency programming spreads, reactive programming has entered mainstream frameworks. Spring now proposes the R2DBC standard, and the vertx framework includes asynchronous connectors for MySQL, PostgreSQL, etc. On the other hand, if an ORM engine acts as a data fusion access engine, its storage might be async-supported NoSQL sources (Redis, ElasticSearch, MongoDB). ORM also needs to cooperate with a GraphQL async execution engine. Given these, NopOrm’s OrmTemplate adds an asynchronous invocation mode:
- Ash Framework – Model your domain, derive the rest
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Java News: WildFly 36, Spring Milestones, and Open Liberty Updates
The sixth release candidate of Eclipse Vert.x 5.0.0 provides support for the Java Platform Module System and a new VerticleBase class. Further details are available in the release notes.
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Rust, C++, and Python trends in jobs on Hacker News (February 2025)
I see your point, but I still don't think you can just say "If you want to get get a job as a Go developer, you must know gRPC." Even more so for Kafka, I've only heard about it being popular in the Java world. You can't even say "If you want to get a job as a Java developer, you must know Spring." Nowadays, sane Java projects use https://vertx.io, it's just too good. I would argue that Spring is for legacy projects only.
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Error handlers and failure handlers in Vert.x
Vert.x is a toolkit for developing reactive applications on the JVM. I wrote a short introductory post about it earlier, when I used it for a commercial project. I had to revisit a Vert.x-based hobby project a few weeks ago, and I learned that there were some gaps in my knowledge about how Vert.x handles failures and errors. To fill those gaps, I did some experiments, wrote a few tests, and then wrote this blog post.
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Spark – A web micro framework for Java and Kotlin
https://vertx.io/
It's actively maintained with full time developers, performant, supports Kotlin out of the box, and has more features?
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Reactive database access on the JVM
Hibernate Reactive integrates with Vert.x, but an extension allows to bridge to Project Reactor if wanted
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Looking for a coroutine-based message broker implementation for inter-app communication.
Have you looked at Vert.x?
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What's the state of server-side frameworks with Kotlin support today for small teams?
Explicitly so:
What are some alternatives?
When comparing RxJava and Vert.x you can also consider the following projects:
reactor-core - Non-Blocking Reactive Foundation for the JVM
Akka - A platform to build and run apps that are elastic, agile, and resilient. SDK, libraries, and hosted environments.
Mutiny - An Intuitive Event-Driven Reactive Programming Library for Java
Zuul - Zuul is a gateway service that provides dynamic routing, monitoring, resiliency, security, and more.
Reactive Streams - Reactive Streams Specification for the JVM
ZIO - ZIO — A type-safe, composable library for async and concurrent programming in Scala