How does Node.js handle concurrency?

Short answer: Node.js uses a single-threaded event loop to handle many I/O operations asynchronously, allowing it to handle thousands of concurrent connections efficiently without creating threads per connection.

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.