What is an API Gateway, and how does it fit into microservices architecture?

Short answer: An API Gateway is a server that acts as an entry point for all client requests to the backend services in a microservices architecture.

Explain a bit more

It acts as a reverse proxy, routing requests from clients to the appropriate microservice, handling common concerns such as security, logging, monitoring, and rate-limiting. How it fits into microservices architecture: It abstracts the complexity of interacting with multiple services and provides a unified interface to clients. It helps with centralized control of common concerns, improving scalability and maintainability. It simplifies the client-side by consolidating multiple service endpoints into a single entry point.

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.