What are child processes and how are they used?

Short answer: Child processes are separate processes spawned by your Node.js app to run shell commands or other programs, enabling parallel execution. const { exec } = require('child_process'); exec('ls -la', (err, stdout, stderr) => { if (err) console.error(err); console.log(stdout); }); Useful for running system commands or scripts without blocking your main app.

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.