Proxy
An intermediary server that sits between the client and the destination server. Forward proxies act on behalf of clients; reverse proxies act on behalf of servers.
What is Proxy?
An intermediary server that sits between the client and the destination server. Forward proxies act on behalf of clients; reverse proxies act on behalf of servers.
Proxy is a foundational concept that sits in the Load Balancing & Proxies 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 "Proxy" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
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Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
Open the Proxy lessonRelated lessons
Lessons that touch on Proxy as part of a larger topic.
Forward Proxy
A middleman that sits between clients and the internet, hiding who's asking
foundation · load balancing proxies
Reverse Proxy
A middleman that sits in front of servers, hiding what's behind it
foundation · load balancing proxies
Ambassador Container Pattern
A specialized sidecar that handles outbound connectivity, connection pooling, retries, and protocol translation for external services
intermediate · microservices architecture
Proxy Pattern
Control access to an object by placing a surrogate in front of it, caching, security, and lazy loading in one pattern
intermediate · microservices architecture
Server-Side Caching
Caching at the server and infrastructure level, reverse proxies, CDNs, and full-page caching
foundation · caching strategies
See also
Related glossary terms you might want to look up next.
Reverse Proxy
A server that sits in front of your backend servers and forwards client requests to them. Handles SSL termination, caching, and load balancing.
Load Balancer
Distributes incoming traffic across multiple servers so no single server gets overwhelmed. Like a traffic cop directing cars to different lanes.
API Gateway
A single entry point for all client requests that routes them to the appropriate microservice. Handles auth, rate limiting, and request transformation.