Discuss Memory Management: How do you debug a heap out-of-memory error in a production Node.js environment?

Analyze Heap Snapshots using Chrome DevTools or v8-profiler, monitor GC logs, and use the --max-old-space-size flag cautiously.

A heap OOM usually occurs when the V8 garbage collector cannot free up enough memory to satisfy an allocation. Debugging involves: 1. Generating a heap snapshot (--inspect or v8.getHeapSnapshot()), 2. Using 'Comparison' view in DevTools to find growing objects, 3. Checking for closures retaining large scopes, 4. Identifying unclosed event listeners or growing global arrays.