Identifying Data Quality Issues Before They Poison Decisions

Daily event volume monitoring

Simple rule: if daily event volume is 30% off the 7-day average, investigate. Most tracking breakages show up here.

Cross-source reconciliation

GA4 says X orders. Shopify says Y orders. They're never identical. But if the gap widens suddenly, something broke.

Session quality checks

Random spot-check 5 sessions per day. If bot traffic or spam shows up, your reports are dirty.