SCD at Pipeline Scale

Conceptual SCD is easy. SCD at 100M+ dimension rows with daily updates is where interviews get hard. This section covers the operational pain points that only surface at scale, and the vocabulary that tells the interviewer you have lived through them. The Four Scale Questions Interviewers Use to Probe Depth Incremental vs Full Rebuild The senior answer: 'We run incremental SCD daily for speed, and a full rebuild weekly as a reconciliation step. If the full rebuild produces different results, we have a bug in the incremental logic.' This dual strategy is standard at Airbnb, Uber, and Netflix. Vocabulary That Signals Seniority The Closing Move Your closing move: 'I would also add a data quality check that counts inferred members older than 7 days. If that count is growing, it means our dimen