Data Migration Scripts

This helps you write database migrations that won't wreck your production data at 2am. It covers schema changes, data transformations, and cross-database moves with built-in rollback capabilities and batch processing for large datasets. The reference guides include working examples for Knex.js and Alembic, plus patterns for zero-downtime deployments using feature flags and backwards-compatible changes. The best practices section is solid on the fundamentals: always write reversible migrations, test on production-like data, use transactions, and never modify old migrations. If you're doing anything beyond trivial schema changes or need to backfill data without taking the site down, this gives you the scaffolding to do it safely.