Spec Driven Development

This is a structured three-phase methodology for breaking down features into Requirements (using EARS format for acceptance criteria), Design (architecture and technical decisions), and Tasks (sequenced implementation steps). It shines when you're building complex features where rework is expensive or when working with AI assistants that need clear structure to generate quality code. The checklists and traceability between phases help catch gaps early. Skip it for simple bug fixes or quick prototypes, but for anything involving multiple components or team collaboration, the upfront investment pays off in reduced ambiguity and fewer surprises during implementation. Essentially turns "build a user authentication system" into a spec you can actually execute against.