Most articles about database migrations assume you know the final model before you start. In real products, you often don't. You ship a design, it goes to production, and then a customer conversation tells you the design was wrong. In 2026, I designed and built a speaker roles feature for an event platform, end to end: database schema, GraphQL API, and changes to both the organizer dashboard and the attendee-facing event app. I shipped it as a one-to-one relationship. After it was live, the r...