I Stopped Vibe Coding and Started Using Prompt Contracts, Here's What the Data

You asked Claude Code to build a Supabase auth flow with row-level security. You got a flawless, production-grade Firebase auth system. Technically impressive. Fundamentally wrong. 2,400 lines of perfectly clean code, deleted at 2 AM. That's the story that kicked off Philippe Eveilleau's viral Medium post — and it hit because every developer using Claude Code has a version of that story. Maybe yours was a payment integration that worked in staging and silently failed in production. Maybe it was an auth system that inverted a truthy check and gave deactivated accounts admin access for two weeks. Maybe it was just a function that passed your test case and rejected every international email address your users actually had. The pattern has a name now. The industry has data on it. And there's a method that actually fixes it — one that Eveilleau formalized as Prompt Contracts, which has now been turned into a book, a framework, and a workflow that developers are genuinely shipping with. Let'