Debugging Data
The dashboard is wrong. Working from a number back to its source through models, joins, partitions and ingestion — and the anti-patterns that made it wrong in the first place.
The domain's closing question. Ten things you have to be able to answer about a figure before you are entitled to act on it — and what it means when you cannot answer one.
Finance and growth disagree about revenue. Both queries are correct. This is almost always a governance failure wearing the costume of a bug.
The report is low, no task failed, and the source database still has every record. Working from a shortfall back to the arrow that dropped it.
Revenue is up, nothing launched, and every check is green except uniqueness. Inflation is the failure people question least and notice last.
A complete, plausible, internally consistent number for a day that ended two days ago. The failure mode that looks most like health.
The domain's thesis, turned into a diagnosis. A green DAG proves the code ran; eight faults, six checks and the distinct fingerprint each one leaves are what prove anything else.
Sixteen decisions that were reasonable when they were made and expensive by the time anyone noticed. Each one gets the argument for it before the argument against.
The six failures that are organisational rather than technical. None of them is visible in a query plan, all of them are cheap in a small company, and each is what a large one means when it says the data cannot be trusted.