Real-world applications suffer from bottlenecks due to:
Performance optimization is about finding the actual slow parts, then fixing them with minimal disruption.
| Area | Strategies |
|---|---|
| I/O | Use non-blocking APIs, streams, connection pooling |
| Loops & Logic | Avoid nested loops, debounce/throttle expensive calls |
| GC Pressure | Avoid long-lived large objects, clear caches, reuse buffers |
| Database | Use indexes, limit queries, batch inserts, lazy loading |
| Caching | Use in-memory stores (Redis), memoization, CDN for static assets |
| Concurrency | Use Clustering, Worker Threads, or offload to background queues |
Your Node.js app hits 100% CPU under load, despite minimal traffic. You profile it and realize:
JSON.stringify() on massive data is blocking the event loop.You rewrite using streaming + background job + in-memory cache → 10x faster.
clinic.js (includes doctor, flame, bubbleprof)