prototypelisted

> Source: [mattpocock/skills - engineering/prototype](https://github.com/mattpocock/skills/tree/main/skills/engineering/prototype) # Prototype A prototype is **throwaway code that answers a question**. The question decides the shape. ## Pick a branch Identify which question is being answered - from the user's prompt, the surrounding code, or by asking if the user is around: - **"Does this logic / state model feel right?"** -> [LOGIC.md](LOGIC.md). Build a tiny interactive terminal app that pushes the state machine through cases that are hard to reason about on paper. - **"What should this look like?"** -> [UI.md](UI.md). Generate several radically different UI variations on a single route, switchable via a URL search param and a floating bottom bar. The two branches produce very different artifacts - getting this wrong wastes the whole prototype. If the question is genuinely ambiguous and the user isn't reachable, default to whichever branch better matches the surrounding code (a backend module -> logic; a page or component -> UI) and state the assumption at the top of the prototype. `(review-time: branch-selection judgment from the question shape)` ## Rules that apply to both 1. **Throwaway from day one, and clearly marked as such.** Locate the prototype code close to where it will actually be used (next to the module or page it's prototyping for) so context is obvious - but name it so a casual reader can see it's a prototype, not production. For throwaway UI routes,