Django migration rollback strategy for CI/CD deployments

Problem: How to handle Django migration rollbacks in CI/CD? Code rollback is easy, but migrations are already applied. If migrations drop/rename fields, rolling back code breaks the app.

Best practice: Never rollback migrations. Only roll forward.

Strategy 1 - Keep migrations backward-compatible (expand/contract):

# ❌ Bad - Breaking change
migrations.RemoveField('User', 'email')
migrations.AddField('User', 'email_address', ...)

# ✅ Good - Expand/contract pattern
# Migration 1: Add new field
migrations.AddField('User', 'email_address', null=True)
# Deploy code to use both fields
# Migration 2 (later): Remove old field
migrations.RemoveField('User', 'email')

Strategy 2 - Make migrations reversible:

operations = [
    migrations.RunPython(
        code=forwards_func,
        reverse_code=backwards_func
    ),
]

Strategy 3 - Use SeparateDatabaseAndState for destructive ops:

migrations.SeparateDatabaseAndState(
    state_operations=[migrations.RemoveField('User', 'old_field')],
    database_operations=[]
)

CI/CD: If migrate fails, entire deploy fails. Previous code keeps running. Fix migration and redeploy.

Source: https://www.reddit.com/r/django/comments/1r1t7xq/how_do_you_handle_django_migration_rollback_in/