When 30% of Ad Conversions Vanished
A major streaming platform noticed a growing gap between what their DSP partner reported and what their internal attribution system counted. By the time they called me, the discrepancy had grown to 30% — meaning nearly a third of conversions were invisible to their optimization team.
The root cause turned out to be a timezone mismatch in the event ingestion layer. Conversion events arriving near midnight UTC were being assigned to the wrong attribution window, causing them to fall outside the lookback period and get silently dropped. The fix was surgical — a timezone normalization step in the Airflow DAG — but finding it required tracing events across three systems and two cloud providers.
Result: Full conversion visibility restored within one week. The client estimated the fix recovered $2.4M in annual optimization value that had been invisible to their bidding algorithms.