Everyone teaches you to write prompts. In practice, a person looks at a sample a couple of pages long, with a stack, constraints, formats and edge cases, and closes the tab: there's no way I'll write that.

I needed a document camera: an Android phone on a tripod above the desk, a live preview in the PaperLedger browser page and a "Capture" button. Instead of a technical specification I told the agent: interview me, find out the stack, the architecture and the boundaries of the decisions.

An hour later there were 72 messages from me and 71 answers from the agent. Some of the questions were ones I would never have thought of myself: for example, what happens if the portal is open in several tabs at once. There was also a mistake by the agent: it questioned me at length about integration with PaperLedger before looking at its code.

I never wrote the final "prompt". It came together from the answers: the scenario, the boundaries, the contract between the phone and the portal.…