Zero to one with AI: what changes in the lean loop

Working notes. The full essay is in progress; this is the argument in outline.

The claim

The lean UX loop assumes deterministic software: design a flow, test it, ship it. AI products break two of the three steps. The loop survives, but every stage needs a new instrument.

What I have seen change

• Prototyping: at Inworld the artifact was often a behavior, not a screen. The Narrative Graph exists because authoring behavior needed a visual grammar of its own.
• Research: a UXR program handbook cut our testing costs by 39% while raising CSAT 23%; with AI products you test distributions, not paths.
• Shipping: 30 features in a year is possible only when design, research, and systems are separate pillars that trust each other.

The outline

1. The brief is a capability, not a feature.
2. Test the model's failure modes before the happy path.
3. Design systems must theme for uncertainty: loading, confidence, refusal.
4. The 0-to-1 skill that transfers: knowing which corner to cut.