Database Migration Standards Apply these rules when creating or modifying database migrations. Migrations are permanent records of schema evolution and must be treated with extreme care. When to use this skill - When creating new database migration files (db/migrate/, migrations/, alembic/, etc.) - When modifying database schema such as adding, removing, or altering tables and columns - When implementing rollback/down methods for reversible migrations - When creating indexes on database tables, especially large tables requiring concurrent indexing - When writing data migrations to transform o…