API Versioning
Strategies for evolving an API without breaking existing clients. Common approaches: URL path (/v2/users), header (Accept-Version), or query param (?version=2).
What is API Versioning?
Strategies for evolving an API without breaking existing clients. Common approaches: URL path (/v2/users), header (Accept-Version), or query param (?version=2).
API Versioning is a intermediate-level concept that sits in the API Design & Protocols 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 Versioning" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
Learn API Versioning in depth
Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
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API
Application Programming Interface: a contract defining how two pieces of software talk to each other. The waiter between your frontend and your backend.