How do you optimize Node.js applications for high throughput?

Short answer: Avoid blocking the event loop. Use asynchronous APIs. Use clustering or worker threads. Cache results where possible. Profile and fix bottlenecks. Use load balancers for scaling horizontally.

Real-world example (ShopNest)

A ShopNest BFF in Node.js aggregates catalog and price APIs for the React storefront.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.