How do you handle routing, load balancing, and caching with an API Gateway?

Short answer: Routing: The API Gateway routes incoming requests to the appropriate microservice based on the URL, method, or other attributes.

Explain a bit more

It can also aggregate responses from multiple services and return a unified response. Example: Requests to /user are routed to the User Service, and /order to the Order Service. Load Balancing: The API Gateway often integrates with a load balancer to distribute requests across multiple instances of a service, ensuring better resource utilization and failover support. Example: Requests to a microservice like User Service can be distributed among several instances based on a round-robin or least-connections strategy. Caching: API Gateways can cache responses for repeated requests, reducing the load on backend services and improving response times for frequently accessed data. Example: Cache responses to user profiles for 1 minute to avoid querying the User Service on every request.

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.