Anything non-trivial starts as a one-page design doc — the problem, the proposed approach, the tradeoffs, and the open questions.
The author shares the draft with the people closest to the work and iterates on comments before code is written. The goal isn't consensus; it's surfacing the disagreements early.
A good spec is short, opinionated, and easy to argue with. A bad spec is long, hedged, and impossible to disagree with.
