13 CLAUDE.md Rules That Make AI Write Production-Quality Spring Boot Code

If you have ever asked Claude Code, Cursor, or Copilot to "add an endpoint" to a Spring Boot project, you already know the result: a @RestController with field injection, business logic crammed into the controller method, no @Transactional, no validation, a stack trace leaking back to the client, and a test that boots the entire @SpringBootTest context just to assert a 200. That output is not the AI's fault. The training data is fifteen years of Spring tutorials — most of them written for Sprin