A gorgeous v0 front end — with nothing behind it.

v0 is a UI-generation tool. Give it a prompt or a design reference and it returns real, working interface code — styled components assembled out of a standard component library. That's the entire brief it's built against: turn a description into a component tree that renders correctly. It was never asked to infer a database schema, an authorization model, or the server-side code those screens would need to do anything real, so it doesn't produce one.

The result is what front-end engineers have long called a presentational component: something that takes data through props, renders markup from it, and calls back whatever function it's handed on a click. It has no concept of where that data came from or where the click leads. v0 generates exactly that half, and fills the props with plausible sample data so the preview renders convincingly with nothing behind it. The missing half is the container logic: code that fetches real data, checks who's allowed to see it, and does something when the button is pressed.

That split is a reasonable scope, not a shortcut. Generating a component that looks right from a prompt is a bounded, low-stakes problem. Generating a correct data model, authorization rules and migrations from the same prompt is a different order of risk entirely — get it wrong and you leak or corrupt data, not just misalign some padding.

A v0 project is finished on one axis and not started on the other. It needs a second, deliberate engineering pass: replace the mocked props with real data fetching, write the server logic each screen was quietly assuming, and wire real sessions into components built for a signed-in user who was never actually signed in. Skip that pass and the symptoms above are exactly what shows up — a login screen with no session behind it, buttons that render but don't act.