Design a worker pool for processing 100,000 jobs with back-pressure and graceful shutdown.
A worker pool uses a buffered jobs channel for back-pressure, N goroutines as workers, a WaitGroup for tracking completion, and context cancellation for graceful shutdown.
Production-grade worker pool
Design notes
Buffer size controls back-pressure: smaller buffer = tighter back-pressure on producer
Close the jobs channel to signal workers — ranging over a closed channel exits cleanly
WaitGroup ensures all in-progress jobs complete before results channel is closed
For context-aware cancellation, pass ctx to each worker and select on ctx.Done()
Add a dead-letter queue or retry channel for failed jobs in production