Request-Response
The most basic communication pattern: one party sends a request and waits for the other to send a response. HTTP, REST, and gRPC all follow this pattern.
What is Request-Response?
The most basic communication pattern: one party sends a request and waits for the other to send a response. HTTP, REST, and gRPC all follow this pattern.
Request-Response 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 "Request-Response" 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 Request-Response lessonRelated lessons
Lessons that touch on Request-Response as part of a larger topic.
Request-Response Pattern
The most fundamental messaging pattern, send a request, wait for a reply
intermediate · messaging event systems
Synchronous Processing
Sequential request-response pattern where each operation waits for the previous one
foundation · core fundamentals
Request-Reply Pattern
Request-response over messaging, decouple the caller from the responder with queues
intermediate · messaging event systems
See also
Related glossary terms you might want to look up next.
HTTP
The protocol powering the web. A request-response model where clients ask for resources and servers respond. Stateless by design.
Synchronous
A communication model where the caller waits for the operation to complete before moving on. Simpler to reason about but blocks the thread.
Client-Server Model
The foundational architecture of the web: clients (browsers, apps) send requests and servers process them and return responses. Every web interaction follows this pattern.