| name | data-integrity-migration-skill |
| description | Change backend domain models, persistence, schemas, and migrations while preserving invariants, tenant scope, rollback safety, and operational compatibility. |
| allowed-tools | ["read_file","list_dir","grep_search","glob_files","write_file","edit_file","apply_patch","lsp","run_command","artifact_write"] |
Data integrity and migrations
Overview
Treat persisted data as a long-lived contract. Put invariants at the strongest
reliable layer, scope every operation correctly, and design migrations for the
mixed-version and partially completed states that exist during rollout.
When to Use
Use for domain models, repositories, SQL, ORM changes, indexes, constraints,
transactions, data backfills, schema migrations, retention, and tenant-scoped
queries.
Workflow
- Identify the data owner, invariants, tenant or organization key, lifecycle,
volume, access patterns, and every reader and writer affected by the change.
- Choose the strongest enforcement layer: database constraint for stored
invariants, transaction for atomic state changes, and application validation
for user-facing errors. Do not rely on one layer to replace the others.
- Design expand-migrate-contract rollout when old and new code may overlap.
Make backfills bounded, resumable, idempotent, observable, and safe to retry.
- Preserve scope in every read, write, join, cache key, and uniqueness rule.
Add indexes from measured query shapes, not table size guesses alone.
- Define rollback or forward-recovery before applying destructive changes.
Separate irreversible cleanup from the compatibility migration.
- Test constraints, transaction rollback, duplicates, concurrent updates,
partial backfills, empty and large datasets, and cross-scope denial.
Verification
Red Flags
- Destructive schema changes in the same step that deploys new readers.
- A backfill that must finish in one process or one transaction.
- Application-only uniqueness or referential-integrity assumptions.
- Adding an index without checking its write cost and actual query shape.
