Your question is ETL Data Quality and Integrity. Take a moment with it on the right.
Talk me through your thinking if you like. When you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes).
How do you ensure data quality and integrity at each stage of an ETL pipeline?
Describe practical controls for ingestion, transformation, loading, and consumption, including schema validation, completeness, accuracy, uniqueness, referential integrity, reconciliation, observability, and recovery. Include examples of automated checks, quarantine or dead-letter handling, idempotent processing, and how you would prevent invalid data from propagating.