Spec-Driven Development

Spec-Driven Development mandates a machine-readable contract (OpenAPI or GraphQL) as the single source of truth before a single line of application code is written.

This methodology shifts the development bottleneck from manual coordination to automated validation. By defining an API using OpenAPI 3.0 or Smithy specs upfront, teams generate consistent client SDKs, mock servers (Prism), and contract tests (Dredd) instantly. It eliminates the 'drift' between documentation and implementation, ensuring that frontend and backend teams work against a locked interface. High-velocity shops like Stripe and Twilio use this to maintain 99.99% integration reliability while scaling microservices.

https://swagger.io/solutions/design-first-api-development/