phase 2 · 2.3-concurrency-patterns

Worker pool + fan-out/fan-in + context

prereqs 1.5-goroutines-channels 2.2-net-http-server

review intervals 3d 7d 21d 60d drills context-timeout, errgroup-fanout

The lesson for this task hasn't been written yet. The mastery criteria below is the shortest description of what you'll own when this task is green.

Mastery criteria

- HTTP-backed worker pool: N goroutines, bounded queue, clean shutdown
- Fan-out to 3 "upstream" URLs; return the fastest; cancel the stragglers via context
- sync.WaitGroup vs errgroup chosen deliberately, not reflexively

Verify

Run from your go-dojo repo root:

go-dojo verify 2.3-concurrency-patterns

This runs the task's go test suite in exercises/phase-2/2.3-concurrency-patterns/, commits the attempt to .go-dojo/attempts/, and updates your mastery.