# Validate Before You Build

**Track:** Discovery & Validation at AI Speed — AI for Entrepreneurship — complete (29)
**Framework / surface:** venture strategy
**Level:** Intermediate
**Prerequisites:** Prototyping at AI Speed

**In one line:** Concierge tests, Wizard-of-Oz, and fake doors — humans behind the curtain until the model catches up.

## Theory, aesthetics & inspiration

Eric Ries's "The Lean Startup" (2011) defined the minimum viable product as the smallest experiment that produces validated learning, and the classic repertoire predates AI: Zappos began in 1999 with Nick Swinmurn photographing shoes in local stores and buying them retail only when orders arrived — a Wizard-of-Oz demand test, humans behind the curtain where software would eventually go, with no inventory system behind it. Concierge tests do the manual work overtly as a service; fake-door tests measure clicks on a feature that does not exist yet. The exponential gives this old repertoire new force: "humans behind the curtain until the model catches up" is now a strategy with a plausible payoff horizon, because the curtain-work you staff manually this year is a fine-tuning corpus and an eval suite for the model that automates it next year. Validate the demand curve first; the capability curve is coming to meet you.

**Founder question:** What is the cheapest test that could kill this idea this week?