Migration Workflow

Migration Workflow

Quick Start

Task Progress:
- [ ] Step 1: Assess migration scope
- [ ] Step 2: Analyze breaking changes
- [ ] Step 3: Create migration plan
- [ ] Step 4: Execute migration phases
- [ ] Step 5: Validate and verify
- [ ] Step 6: Document and clean up

Step 1: Assess Migration Scope

• Identify the migration type: database schema, framework version, dependency upgrade, language version, or infrastructure change.
• Inventory all affected files, modules, and services.
• Check for transitive dependency impacts — upgrading one package may force others.
• Review the target version's changelog, migration guide, and known issues.
• Estimate effort and risk level (low/medium/high) based on scope.

Step 2: Analyze Breaking Changes

• Compare current vs target API surfaces for changed/removed features.
• Search the codebase for usage of deprecated or removed APIs.
• For database migrations: identify schema changes, data transformations, and index impacts.
• For framework upgrades: check configuration format changes, plugin compatibility, and behavioral differences.
• Document each breaking change with affected file locations and required code modifications.

Step 3: Create Migration Plan

• Define phases with clear boundaries — each phase should be independently deployable and rollback-safe.
• Phase ordering: compatibility layer first, then consumer migration, then removal of old code.
• For database migrations: write both up and down migration scripts. Test both directions.
• Include a rollback plan for each phase with specific steps and time estimates.
• Set validation criteria for each phase before proceeding to the next.

Step 4: Execute Migration Phases

• Implement one phase at a time. Verify before proceeding.
• For dependency upgrades: update lockfile, fix type errors, update API calls, run tests.
• For database migrations: run against a staging copy first, verify data integrity, measure execution time.
• For framework migrations: use codemods where available, manual fixes where not.
• Keep backward compatibility during transition — both old and new code paths should work.

Step 5: Validate and Verify

• Run the full test suite after each phase.
• For database migrations: verify row counts, check constraint integrity, test queries against migrated data.
• For dependency upgrades: verify bundle size impact, check for runtime behavior changes.
• Performance benchmark critical paths before and after.
• Test rollback procedure on a staging environment.

Step 6: Document and Clean Up

• Remove compatibility shims and old code paths after the migration is complete.
• Update project documentation (README, setup guides, deployment docs).
• Update CI configuration if build steps changed.
• Delete unused migration scripts after they've been applied to all environments.
• Write a migration retrospective noting what went well and any issues encountered.

Error Handling

• Migration phase fails partway through: Roll back to the last successful phase checkpoint. Diagnose the failure before retrying. Each phase must leave the codebase in a working state.
• Rollback procedure does not restore original behavior: Treat this as a critical gap. Fix the rollback procedure before proceeding with the migration, since an untested rollback path is a deployment risk.
• Dependency version conflict during migration: Pin the conflicting dependency to the version compatible with the migration target. Document the pin and plan its removal after all consumers are updated.

Definition of Done

• All phases completed and verified
• Full test suite passes
• Rollback procedure tested
• No backward-compatibility shims remain
• Documentation updated
• Performance verified against baseline