Graceful Shutdown

This handles the unsexy but critical work of shutting down your application without dropping requests or leaking resources. It covers the full stack: tracking active connections, rejecting new requests during shutdown, waiting for in-flight work to finish, and cleaning up database pools and other resources. The guides show Express, Flask, PM2, and Kubernetes setups, which is the right mix since shutdown logic varies enough between environments that you can't just copy-paste. The 30-second default timeout is reasonable but you'll want to tune it based on your actual request durations. Worth implementing before your first production incident, not after.