Spec-Driven Development flips the script on traditional software development. For decades, code has been king — specifications were just scaffolding we built and discarded once the "real work" of coding began. Spec-Driven Development changes this: specifications become executable, directly generating working implementations rather than just guiding them.
This is rising in popularity again because of the use of AI. Using a Plan mode with an [[20260413105415-models-and-harnesses]], you can create the spec, properly review it, and then get AI to handle all of the implementation work per the spec.
What a spec is has some debate. Ranging anywhere from 'the spec is the only thing that matters, and the code doesn't', to a mental model similar to [[20260610023222-test-driven-development-tdd]]. A lot of this is very similar to the ideas presented in [[20260601032608-vibe-coding-dangers]] and [[20260604045417-ai-software-development-loops]].