Memory Leaks and Debugging

Monitor Memory

```javascript setInterval(() => { const used = process.memoryUsage(); console.log({ rss: `${Math.round(used.rss / 1024 / 1024)} MB`, heapUsed: `${Math.round(used.heapUsed / 1024 / 1024)} MB` }); }, 60000); ```

Common Causes

```javascript let cache = {};

emitter.on('data', handler);

function createHandler() { const largeData = new Array(1000000); return () => { console.log(largeData.length); }; } ```

**Fixes:** - Use LRU cache with limits - Remove event listeners - Don't reference large data in closures

Key Takeaway

Monitor memory in production. Remove event listeners. Use LRU cache with limits. Take heap snapshots to find leaks.