Independent team decisions lead to API misalignment, causing slow velocity, complex debugging, and backend-driven UI.
Handwritten TypeScript interfaces and documentation inevitably become outdated and cannot enforce API consistency.
Shifting from viewing OpenAPI as documentation to a machine-readable contract enables automated code generation and build-time validation.
The API specification is defined and reviewed first, serving as the single source of truth for both frontend and backend implementation.
Refactoring endpoints to return only domain data, not presentation logic, empowers the frontend to own the user interface completely.
Providing an OpenAPI spec as context to AI tools dramatically improves the accuracy and reliability of generated code like React hooks and test mocks.
Start by requiring a spec for all new endpoints and gradually migrate high-impact existing ones to avoid a disruptive big-bang migration.
Successfully implementing API contracts requires addressing challenges like spec ownership, CI validation tooling, and establishing shared conventions.
The core benefit of a contract-first approach is making implicit agreements explicit, which stops architectural decay and builds trust between systems.
Jobs that call for the skills explored in this talk.