THE SPEC LAYER

Summary from the TLDR newsletter

Spec-driven development means writing durable intent down before implementation, using it to plan, build, check, and revise the work. The goal is to reduce execution freedom. Specs should be declarative, layered, and cheap to revise. When a rule can be enforced mechanically, move it out of the spec and into lint, schemas, tests, or the harness. Specs matter, but they're just one layer. The winning model puts a narrow interface between human intent and machine execution.