What is an API Gateway, and what functions does it serve in microservices?

Short answer: An API Gateway is a server that acts as an entry point into a microservices architecture. It provides a single point of entry for client applications to interact with multiple microservices. Functions of an API Gateway:

Real-world example (ShopNest)

ShopNest’s API Gateway routes /orders to the Order service and /payments to Payment—clients talk to one entry point.

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.