What is rate limiting and how do you implement it?

Short answer: Rate limiting prevents abuse by limiting the number of requests a user can make in a given time. 📌 Use express-rate-limit: npm install express-rate-limit const rateLimit = require('express-rate-limit'); const limiter = rateLimit({ windowMs: 15 * 60 * 1000, max: 100 // limit per IP }); app.use(limiter);

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.