Backend Migrations

Database migrations use up/down scripts to implement schema changes reversibly. Write an up script to add or modify tables and columns, and a corresponding down script to rollback those changes, ensuring you can revert deployments safely and maintain version control of all schema evolutions.

Zero-downtime deployments separate schema changes from data migrations and use strategies like concurrent index creation on large tables. This approach lets you deploy schema updates while the database remains accessible, preventing service interruptions during production releases.

Store migration files in a dedicated directory like db/migrate or database/migrations with descriptive naming conventions. Version-control these files alongside your application code to track all schema changes, enable team collaboration, and maintain a complete audit trail of database evolution.

Separate data migrations from schema migrations by creating distinct migration files for each concern. This approach isolates data transformation logic from structural changes, reduces risk, and allows you to test and deploy schema and data updates independently.

Yes, backward compatibility ensures older application versions continue working during phased deployments. When altering columns or removing fields, use nullable defaults and gradual deprecation patterns to support multiple schema versions until all clients upgrade.