Database Migration Patterns Safe, reversible database schema changes for production systems. When to Activate - Creating or altering database tables - Adding/removing columns or indexes - Running data migrations (backfill, transform) - Planning zero-downtime schema changes - Setting up migration tooling for a new project Core Principles 1. Every change is a migration — never alter production databases manually 2. Migrations are forward-only in production — rollbacks use new forward migrations 3. Schema and data migrations are separate — never mix DDL and DML in one migration 4. Test migration…