// backend engineering pathway

Twelve labs that feel like backend engineering, not puzzle practice.

The first pathway teaches HTTP internals, concurrency, database diagnosis, caching, queues, retries, pprof, and failure handling through build labs and production-style debug labs.

Start with two free labs

v0 mix

12

Labs

6

Debug

6

Build

40+

Concepts

// the roadmap

Four pathways. One production engineer.

Subscribe once. Every pathway unlocks as it ships. Each one is twelve labs built around real incidents — not language tutorials.

Go Backend Production Engineering

Twelve production incidents and the systems behind them — HTTP framing, N+1 queries, Redis OOM, retry storms, goroutine leaks, write-through caches. Real services, real failures, scored on more than 'did it pass.'

  1. 01

    Build a real HTTP server

    Sockets, request parsing, routing. No net/http allowed.

    Build
  2. 02

    REST API returns 500s under concurrency

    Logs are panicking. Find the data race.

    Debug
  3. 03

    LRU cache, 5M ops/sec

    O(1) get/put. Hit the perf target on a single core.

    Build
  4. 04

    Checkout p99: 80ms → 2.3s

    Cache TTL expired and the dashboard lit up. Why?

    Debug
  5. 05

    Token-bucket rate limiter

    Per-key buckets. Survive the included DDoS sim.

    Build
  6. 06

    Postgres CPU pegged at 100%

    5M-row table. EXPLAIN ANALYZE is your friend.

    Debug
  7. 07

    Redis-backed job queue

    At-least-once. Idempotency. Visibility timeouts.

    Build
  8. 08

    Redis memory exploding

    OOM command not allowed. Find the unbounded growth.

    Debug
  9. 09

    Circuit breaker on a flaky downstream

    Fraud-check melts checkout. Build the state machine that fails fast.

    Build
  10. 10

    Cascading retry storm

    Service B is degrading. Service A is making it worse.

    Debug
  11. 11

    Goroutine leak

    Memory creeps. pprof shows 50k stuck goroutines.

    Debug
  12. 12

    Write-through cache

    Stay consistent under Postgres and Redis failure.

    Build
  13. Every lab graded on correctness, latency, memory