2025-01-19 · Go
Compare goroutines and a worker pool
Fan-out looks great until one slow job takes down your latency budget.
Introduction
Spawning a goroutine per request is idiomatic and dangerous at the same time. We measure unbounded concurrency against a bounded pool, then size the queue from real numbers instead of intuition.
Field notes
A few patterns we kept seeing while puttering around Go problems:
- The simple version survived every refactor; the clever version didn’t.
- Documentation written during the work aged far better than documentation written after.
- The second time a problem shows up, it is already a pattern — name it.
A checklist you can steal
- The failure is reproducible with one command.
- The fix has a test that fails without it.
- Someone other than the author has run it on their machine.
Closing
Write the short version future-you will actually read. That is the whole trick.