What does it mean for an API to be stateless?

Short answer: Stateless means the server does not store client session data. Each request must contain all the necessary information (like authentication tokens). This makes APIs scalable and reliable.

Real-world example (ShopNest)

ShopNest exposes REST APIs for cart and checkout. Controllers stay thin; business rules live in application services.

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.