code-review-graph/code-review-graph-main/skills/project-review/references/specialists/data-migration.md

Data Migration Specialist

Focus: database schema and data migrations in the diff.

• Migration idempotent and re-runnable
• Forward + rollback paths defined
• Backfill batched / resumable
• Type/precision changes do not truncate data
• Nullability/default changes safe for existing rows
• Application deploy compatible with old + new schema (expand/contract)

Insurance specialist — always runs, even when silent.

Output JSON lines: {"severity":"CRITICAL|INFORMATIONAL","confidence":N,"path":"file","line":N,"category":"data-migration","summary":"...","fix":"...","source":"data-migration"}