How do you prevent Denial of Service (DoS) attacks in Node.js?

Short answer: Use rate limiting. Validate and sanitize inputs. Avoid blocking event loop. Use security middleware like helmet. Use a reverse proxy with DDoS protection.

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.