Use heap snapshots to identify object retention, check for unclosed resources, and limit data stored in memory.

Memory spikes in a Node.js application can lead to performance issues, slow responses, and even crashes, making it essential to identify the root cause quickly. Begin by capturing heap snapshots to analyze which objects are taking up memory and if they are being retained unexpectedly. Common causes include unclosed resources like database connections, event listeners, or file handlers that hold onto memory even after they are no longer needed. Another source of memory spikes could be excessive data stored in memory during heavy data processing; consider batching data handling operations or storing large datasets temporarily on disk instead of in memory. Optimizing code to release resources promptly and implementing garbage collection-friendly patterns can help control memory usage and prevent spikes, ensuring the app maintains steady performance.