Where To Use What

CDN vs Load Balancer vs API Gateway vs Proxy — when you need each, with real architecture scenarios from static sites to microservices.

Load Balancer

Where to Use What?: System Design

Question : Do you need all of them?

CDN = Reverse Proxy + caching + edge distribution + other features API Gateway = Reverse Proxy specialized for APIs + auth + rate limiting + routing + API policies + distribute request L7 Load Balancer = Reverse Proxy + HTTP understanding + distribute request L4 Load Balancer = Distribute Connection + no HTTP understanding

1. static Website

Small application with multiple servers

L7 Load Balancer

GET /products

POST /checkout

Big application with multiple servers

Authentication

Rate limiting

Request transformation

API-specific routing

Version management

Logging / policies

Big application with multiple servers and microservices

Organization - Website

Reverse Proxy

Forward Proxy

Amazon-style public website

Live Streaming

Streaming Servers

put that data to cdn