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The Simulation Arcade

Engineering,
but with adrenaline.

A live incident simulator for data engineers. Real systems, real bills, real SLO clocks — recompiled from outage post-mortems and dropped onto your pager. One free sim every month; replays last forever.

P2the-reversible-hash·strata.live
on-call · you
The Reversible Hash

We share a user_hash column with an analytics partner so they can join on users without seeing identities. This morning the partner sent back a spreadsheet mapping our user_hash values straight to real email addresses. We used SHA-256 - it's a one-way function. So how did they reverse it?

Time left
09:32
Severity
P2
Category
Incident Response
Live · graded against expert keys, not multiple choice
P1mara.kgraded SRE onLineage Ghost·14m 02sP2rohan_dreplayedThe Small-Files Tax·22m 41sP1jules.rfailed → red herring onHot Partition·P3sam.wgraded Operator onBronze Bleed·31m 18sP2kira.sshipped first fix onSkew Tax·08m 59sP1alex_ttripped 2 red herrings onThe Optimizer·P1noor.kgraded Veteran onPII Fundamentals·19m 44sP3pieter.vtopology cleared onQuery Engines·12m 02sP1mara.kgraded SRE onLineage Ghost·14m 02sP2rohan_dreplayedThe Small-Files Tax·22m 41sP1jules.rfailed → red herring onHot Partition·P3sam.wgraded Operator onBronze Bleed·31m 18sP2kira.sshipped first fix onSkew Tax·08m 59sP1alex_ttripped 2 red herrings onThe Optimizer·P1noor.kgraded Veteran onPII Fundamentals·19m 44sP3pieter.vtopology cleared onQuery Engines·12m 02s
Anatomy of a sim · 4 phases

Not a tutorial. A diagnosis loop on a clock.

Every sim runs the same four-phase loop the best on-call engineers run in their head. Skip a phase, get graded down. Trip a red herring, lose the clock.

Hunt clues in the right component.

You're handed a topology and a brief. Open the components you think matter. Wrong probes burn time. Wrong layers burn red herrings against your grade.

  • Pick component → run probe → inspect output
  • Evidence chips accumulate at the bottom
  • 4 clues per sim · 1 right answer per layer
small_files_tax.sim · phase 109:32
1 · Investigate
2 · Connect
3 · Causes
4 · Fix
Kafka0/4
Spark1/4
Parquet0/4
Iceberg1/4
Compaction0/4
Trino0/4
$ gsutil du -h …/metadata/v00091821.metadata.json
412M …/metadata/v00091821.metadata.json
[warn] metadata.json grew 412 MB (was 6 MB seven days ago)
[ok] clue captured · evidence chip added
▣ metadata.json sizeclue found
What's actually on the line

The stakes aren't theoretical.
They're the bills you've actually paid.

Every scenario is recompiled from a real outage post-mortem. Same systems, same metrics, same root causes — we change the names so the lawyers stay calm.

Cloud bill
+$48k/wk
Class-B LIST ops at 38M/day. The CFO has already flagged this one — you have until the next billing snapshot.
SLO clock
73:00
Daily revenue rollup fails next run. Once the deadline hits, the dashboard execs check at 9am is empty.
Query p99
+412%
Latency drift on stale Iceberg manifests. The analytics team is already in your DMs about it.
Grade on record
Apprentice
First finish is the score that ships to your profile. Replays earn XP — they don't overwrite the grade.
1 game type · 5 live · 3 scheduled

Every Monday, a new ticket.
Last Monday of the month — free for everyone.

Browse all 8 games
SEVIncidentDifficultyStatus
four phase6 of 8
P2
The Reversible Hashthe-reversible-hash · Incident Response · free drop
easy
Free
P2
The Small-Files Taxthe-small-files-tax · Incident Response · free drop
medium
Free
P1
The Anonymization That Wasn'tthe-anonymization-that-wasnt · Incident Response
hard
drops Jul 2
⊘ soon
P1
The Regex Blind Spotthe-regex-blind-spot · Incident Response
medium
drops Jun 27
⊘ soon
P1
The Ghost in the Snapshotthe-ghost-in-the-snapshot · Incident Response
medium
drops Jun 22
⊘ soon
P1
The Hot-Shard Spiralthe-hot-shard-spiral · Incident Response
hard
Live
Browse all 8 games →
● A new drop every Monday

One free simulation every month.
Unlock the rest for the price of one bad query.

A new drop every Monday. The last drop of the month is free for everyone, no card. Annual saves ~50%. Cancel anytime, replays last forever.

See full pricing →
$14.99/mo · monthly$89.99/yr · saves ~50%$0 · last drop of every month