How do you handle schema migrations safely in a production Spring Boot application?

Use Flyway or Liquibase: 1) Every schema change is a versioned migration file: V2024_01_15__add_status_column.sql. 2) Migrations run automatically on application startup (flyway.baseline-on-migrate=true for existing schemas). 3) Backward-compatible migrations: add nullable column first, deploy app, then add NOT NULL/backfill. 4) Zero-downtime deployment requires schema compatible with both old and