API-First Design
Development approach that treats APIs as primary products requiring careful design.
Definition
API-first design is a development philosophy that treats APIs as primary products deserving the same careful design attention as user interfaces. Rather than creating APIs as afterthoughts to expose existing functionality, API-first teams design APIs upfront as the foundation of their systems.
This approach results in more consistent, usable, and maintainable APIs. API-first design typically involves collaborative API specification (often using OpenAPI), mocking for parallel development, and treating API documentation as a first-class concern.
Why It Matters
APIs are the building blocks of modern digital experiences. Well-designed APIs enable faster integration, better developer experience, and more flexible architectures.
For technical teams, API-first thinking prevents the debt of poorly designed APIs that plague many organizations.
Examples in Practice
A company designs their API specification collaboratively before implementation, enabling frontend and backend teams to work in parallel.
API-first design includes a developer portal with interactive documentation, reducing integration time for partners.
A platform's well-designed API becomes a competitive advantage, attracting third-party developers who extend its ecosystem.