A TinyCTO.tv Hype Stack technical parable about single-user assumption, concurrency, state collision. Test concurrency, tenancy, isolation, and state ownership before treating a single-user demo as a product.
"# Episode 129 — The App Worked Until a Second User — Script"
"## Concept single-user assumption;concurrency;state collision"
"## Hype promise A prompt can turn an idea into a production-ready product before the meeting ends."
"## System reality The app stores session state globally and works perfectly until a second user arrives."
Risk approval is not risk ownership unless the decision is tied to people who can act when the risk becomes real.