
Spec-Driven Development: It Looks Like Waterfall (And I Feel Fine)
We’ve been talking a lot about agentic engineering, how software is now getting built with AI. As I look to see how design can complement this new development paradigm, a newish methodology called spec-driven development caught my eye. The idea is straightforward: you write a detailed specification first, then AI agents generate the code from it. The specification becomes the source of truth, not the code.
My first reaction when I started reading about SDD was: wait, isn’t this just waterfall?
Seriously. You gather requirements. You write them down in a structured document. You hand that document to someone (or something) that builds to spec. That’s the waterfall pattern. We spent two decades running away from it, and now it’s back wearing a blue Patagonia vest and calling itself a methodology.




























