integration-testing skill helps verify that different components of the system work together correctly through end-to-end testing and contract testing.

For code review, check that:
1. Critical user journeys are tested end-to-end
2. API contracts are tested with provider tests
3. Database integration is tested
4. External service integrations are tested
5. Test data is properly isolated
6. Tests are deterministic and repeatable
7. Test environments mimic production
8. Performance tests cover critical paths
9. Error scenarios are tested
10. Test coverage includes all integrations