The Night Our Analytics Automation Became a Fortune Teller (and Saved Our Launch)
At 11:47 p.m., our analytics automation pinged Slack: "Forecasted checkout drop in 6 hours: -18% vs baseline. Primary driver: mobile Safari cart errors." We laughed-until we opened the dashboard and saw it: a subtle spike in "add_to_cart" followed by a quiet cliff in "begin_checkout," only on iOS 17. It wasn't magic. We'd stitched together event streams, a simple anomaly model, and a rule that cross-checked device + browser segments before firing an alert. Here's the practical part: we were logging frontend errors but not tying them to revenue events. The automation did. It correlated a new JS bundle release at 9 p.m. with rising "TypeError" counts and a widening gap between cart and checkout. We flipped the feature flag, rolled back the bundle, and watched conversion recover within 20 minutes. Next, we added a "pre-mortem" report to every release: top 5 risk segments, expected metric drift, and a 2-hour watch window. If you...