Common causes of Memory Leaks in Node.js.

How to Explain in an Interview:

1. Global variables: Accidentally holding references to large objects in global scope.
2. Uncleared event listeners: Repeatedly attaching .on('event', fn) to long-lived objects without .off().
3. Unbounded caches: Storing items in plain JavaScript objects/maps without LRU eviction.
4. Closures: Functions retaining outer scope variables that reference heavy objects.

const v8 = require('v8');
const fs = require('fs');

// Diagnostic: Dump heap snapshot for Chrome DevTools analysis:
function snapshotMemory() {
  const snapshotStream = v8.getHeapSnapshot();
  const fileStream = fs.createWriteStream(`heap-${Date.now()}.heapsnapshot`);
  snapshotStream.pipe(fileStream);
}