How do Spring Data JPA's derived query methods like `findByEmailAndStatus` actually work?

Spring parses the method name at startup, splitting on keywords (`findBy`, `And`, `OrderBy`) and mapping each segment to an entity field, then generates the equivalent JPQL/SQL automatically — no method body is written. This only works for reasonably simple queries; anything with joins across multiple unrelated conditions or dynamic filters is better as an explicit `@Query` or a Criteria API query.