A warehouse gets bought as a single source of truth and quietly becomes several, because raw events do not arrive carrying the metrics people argue about. Google notes that its interface applies its own session-level attribution and that this cannot be reproduced from the exported data, and it lists session counting, metric scope and time zones as the usual reasons two people reach two different totals. So whoever writes the query decides what counts as a session, which channel gets the conversion, and where the day starts. That rarely gets written down, so the client hears one number from the dashboard and another from an analyst, and the argument the warehouse was meant to end reappears in SQL.

The second mistake is treating the load as permanent infrastructure. A standard property that consistently exceeds 1 million events a day has its daily export paused, and the days it missed are not reprocessed, so the hole is there for good while the dashboard on top keeps rendering as though nothing happened. Archon Labs finds gaps like that in warehouses nobody had reason to doubt, usually a quarter later in a year-on-year comparison.