Testing Transforms

Concepts: paDataQuality

What They Want to Hear 'Three layers: unit tests (seconds, test individual transforms on mock data), integration tests (minutes, test end-to-end with a real database), and data diff tests (hours, compare production output before and after a change). Each layer catches different bugs. Unit tests catch logic errors. Integration tests catch environment issues. Data diffs catch subtle regressions that unit tests cannot anticipate.'