Node.js Performance: Optimize Speed and Cut Server Costs

Node.js is known for performance, but poorly optimized code can negate these advantages. At Softechinfra, our CTO Rishikesh Baidya has optimized Node.js applications serving millions of requests—here are proven techniques.

Understanding Node.js Performance

The Event Loop

Node.js is single-threaded with an event loop. Understanding this is key to optimization:

Code-Level Optimizations

Async Best Practices

Memory Management

• Clean up event listeners when done
• Close database connections properly
• Clear timers with clearTimeout/clearInterval
• Use streams for large files instead of loading into memory

Database Optimization

Query Optimization

Connection Pooling

Always use connection pools for databases. Configure max connections, idle timeouts, and connection limits based on your workload and database limits.

Caching Strategies

This is how we built TalkDrill—caching user sessions and practice data in Redis for sub-100ms response times across distributed instances.

Scaling Strategies

Cluster Mode

Node.js is single-threaded, but your server has multiple CPU cores. Use cluster mode to spawn workers for each core, multiplying throughput.

Load Balancing

• Use PM2 for process management and automatic restarts
• Nginx for reverse proxy and load balancing
• Horizontal scaling with multiple instances
• Health checks for routing to healthy instances

For containerized deployments, see our Kubernetes production guide.

Profiling and Monitoring

Key Metrics to Track

• Event loop lag (should be < 100ms)
• Memory usage and heap growth
• CPU utilization per worker
• Response times (p50, p95, p99)
• Error rates and types

Common Mistakes to Avoid

Real-World Optimization

Key Takeaways

• Understand the event loop—don't block it
• Use Promise.all() for parallel operations
• Implement connection pooling for databases
• Cache strategically—Redis for distributed systems
• Use cluster mode to utilize all CPU cores
• Profile before optimizing—find real bottlenecks