How would you manage rate limiting, authentication, and authorization using an API Gateway?

Short answer: Rate Limiting: Use the API Gateway to limit the number of requests a client can make in a given period to prevent abuse and overload. This can be done using libraries or built-in functionality in the gateway (e.g., NGINX, Kong).

Example code

Limit each client to 100 requests per minute. Authentication: The API Gateway can integrate with external identity providers (e.g., OAuth 2.0, JWT) to authenticate requests. It verifies the client's identity before forwarding requests to the microservices. Example: If a request includes a valid JWT token, the gateway passes it along; otherwise, it responds with an authentication error. Authorization: The API Gateway can handle Role-Based Access Control (RBAC) by verifying user roles from the authentication token (JWT) and enforcing access restrictions based on the user's privileges. Example: Only admins can access /admin endpoints, while regular users can access /user endpoints.

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.