Spec-Driven Development for Brownfield: Verify Code Against Intent With a Verifiable Code Context Layer
Specs and code drift apart the day after you write the PRD, because they are two separate documents that nobody keeps in sync. A verifiable context layer derives the spec a codebase actually implements and then continuously checks the code against it. Here is how spec-driven development works on a brownfield codebase, and why it needs a verifiable code IR that checks code against intent.