API Gateway
A single entry point for all client requests that routes them to the appropriate microservice. Handles auth, rate limiting, and request transformation.
What is API Gateway?
A single entry point for all client requests that routes them to the appropriate microservice. Handles auth, rate limiting, and request transformation.
API Gateway is a foundational concept that sits in the Core Fundamentals area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "API Gateway" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
Learn API Gateway in depth
Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
Open the API Gateway lessonRelated lessons
Lessons that touch on API Gateway as part of a larger topic.
API Gateway
Centralized entry point that handles authentication, rate limiting, routing, and request transformation for microservices
foundation · load balancing proxies
Design an API Gateway
Design an API gateway - request routing, authentication, rate limiting, circuit breaker, load balancing, and observability
capstone · capstone
API Gateway Security
Centralizing authentication, rate limiting, and threat protection at the API gateway layer
intermediate · security architecture
See also
Related glossary terms you might want to look up next.
Load Balancer
Distributes incoming traffic across multiple servers so no single server gets overwhelmed. Like a traffic cop directing cars to different lanes.
Microservices
An architecture where an application is split into small, independent services that communicate over the network. Each service owns its own data and can be deployed separately.
Rate Limiting
Controlling how many requests a client can make in a given time window. Protects your API from abuse and ensures fair usage.