Migration testing verifies data moved correctly from source to target.
Test scenarios:
1. Volume:
- All source records migrated.
- Row counts match.
2. Mapping:
- Source field -> target field correct.
- Transformations applied correctly.
3. Relationships:
- Lookups / master-detail pointing right.
- No orphaned children.
4. Quality:
- No nulls in required fields.
- Picklist values valid.
- Date formats correct.
5. Sample reconciliation:
- Spot-check 100+ records source vs target.
- Confirm content preserved.
6. Reports:
- Critical reports work post-migration.
- Aggregates match source.
7. Sharing:
- Owners set correctly.
- Sharing rules apply correctly.
8. Edge cases:
- Records with attachments.
- Special characters.
- Long text fields.
- Records with deleted parents.
Approach:
- Multiple test passes — small sample, partial volume, full volume.
- Reconciliation reports — automated comparison.
- Manual spot checks.
- Test in Full Sandbox before production.
Common pitfalls:
- Insufficient test passes.
- Not testing edge cases.
- No reconciliation reports.
Senior insight: migration testing is high-stakes. Production cutover happens once; defects expensive to fix.