MY ONE BLOGby Manishdai
Cloud & DevOps

What is API Gateway?

Quick answer

A server that sits in front of backend services and handles routing, authentication, rate limiting, and monitoring for API requests.

API Gateway, explained

In a system built from many microservices, clients would otherwise need to know the address of every service. An API gateway provides a single entry point. It receives each request, checks credentials, applies policies, and forwards the call to the right service.

Typical gateway features include request routing, authentication, rate limiting, caching, request transformation, and logging. For example, a mobile app might call one gateway endpoint for user profiles and orders, while behind the scenes the gateway sends those calls to two separate services. Managed options exist on major cloud platforms, and open-source gateways are also widely used. The trade-off is an extra network hop and a component that must be highly available.

Related terms

API

Application Programming Interface: a defined set of rules that lets one piece of software request data or services from another.

Load Balancer

A system that distributes incoming network traffic across multiple servers so no single server is overwhelmed.

Microservices

An architecture style in which an application is built as a collection of small, independent services that communicate over APIs.

Rate Limiting

Restricting how many requests a user, device, or application can make to a service within a set time period.

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