spec-driven-development

Spec-driven development prevents scope drift by capturing raw requirements, designing solutions, and validating behavior before coding. It uses a six-phase workflow with explicit approvals between each phase to ensure product teams and engineers align on features.

To document requirements before coding, create specs/[feature-name]/instructions.md with raw requirements. Then progress through the six phases—Requirements, Design, Behaviors, Plan, and Implementation—prompting for user sign-off after each phase to ensure alignment.

A phase-based workflow should be used for new features, major refactors, API design, and complex bugs. It guides the process by producing living specifications and executable behavioral tests that drive implementation and serve as ongoing reference.

Yes, spec-driven development produces executable behavioral tests attached to features. These tests satisfy testing requirements by driving implementation and serving as living documentation throughout the software engineering lifecycle.

Yes, structured planning applies to major refactors and API design. The six-phase spec-driven workflow captures functional, non-functional, and data requirements, ensuring disciplined delivery and living documentation for complex engineering tasks.

The six-phase spec-driven workflow requires explicit user authorization after each phase, which may slow down rapid prototyping. It is designed for complex features and refactors where avoiding scope drift outweighs the overhead of phase-by-phase approvals.