Spec-Driven Development

Andrej Karpathy recently gave a talk called "From Vibe Coding to Agentic Engineering." One line stuck with me: "People have to be in charge of this spec, this plan. Work with your agent to design a spec that is very detailed." He is describing what happens when you stop treating AI as a magic text box and start treating it as something that builds from structured input. The casual approach works for small things. A quick script, a throwaway page, a one-off function. The moment the problem gets r