High memory usage and slow performance usually indicate memory leaks or inefficient code. Profiling and optimizing code can help.

When a Node.js application experiences high memory usage and slow performance, it’s often due to memory leaks, inefficient loops, or intensive operations blocking the event loop. Profiling tools like Node’s built-in --inspect flag with Chrome DevTools can pinpoint memory-intensive processes, showing functions or modules consuming excessive resources. One common issue involves storing too many objects in memory or creating closures in long-lived objects, preventing garbage collection and causing memory bloat. Reviewing code for patterns like continuously appended arrays or adding event listeners without removing them can reduce unnecessary memory consumption. Moreover, async functions that are improperly managed may result in excessive call stacks, adding memory burden. Another critical factor is using synchronous methods in CPU-bound tasks, which can block the event loop and slow down the whole application. Converting these operations to asynchronous functions or offloading them to worker threads can mitigate blocking issues. Database connections, too, can impact memory if left open; implementing proper pooling strategies ensures connections are recycled efficiently. Optimizing code, reviewing modules, and using external tools like clinic.js for automated profiling can help track memory bottlenecks and restore responsive performance.