How to build a job queue in Go without external dependencies

Most job queue tutorials start with Redis, RabbitMQ, or some managed queue service. That's fine for teams with existing infrastructure — but if you're building an internal tool, a side project, or a microservice that needs to process tasks asynchronously, pulling in a message broker is overkill. Go's standard library gives you everything you need: goroutines, channels, sync primitives, and context for cancellation. What we're building A concurrent job queue with: A fixed pool of workers pulling from a buffered channel Non-blocking enqueue — full queue returns an error, no caller hangs Per-job retry with a configurable limit Graceful shutdown on SIGINT/SIGTERM — no jobs dropped mid-flight An error channel so worker failures don't crash the process Around 150 lines of Go. No external libraries. The core structure package queue import ( "context" "fmt" "sync" ) type Job struct { ID string Payload any Retries int Ma