What is PM2 and why is it used?

Short answer: PM2 is a popular production process manager for Node.js applications. It helps you: Manage and keep apps alive forever (auto-restart on crashes). Run apps in cluster mode easily. Monitor resource usage (CPU, memory). Handle zero-downtime reloads. npm install pm2 -g pm2 start app.js -i max # Runs in cluster mode with max CPU cores

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.