Node.js async_hooks tracks execution context across async boundaries. It powers Datadog, New Relic, and OpenTelemetry. Understanding it lets you build request tracing, correlation IDs, and automatic logging without threading context through every function call.

Node.js is single-threaded, but your server has 8 CPU cores sitting idle. The cluster module spawns one worker per core, routes traffic between them, and enables zero-downtime restarts — no orchestration needed.

Node.js streams with unhandled backpressure silently consume all available memory until your server crashes. Here is how to detect it, understand it, and fix it permanently.

Event loop blocking silently destroys Node.js API performance under load — no errors, no crashes. Here's how to find it, measure it, and fix it permanently with worker threads.