Data engineering·Quality, tests and knowing it is wrong
you count the rows in the source and in the warehouse for the same period and prove that the numbers agree.
Row-count reconciliation
Also calledsource-to-target reconciliation, count matching
Comparing aggregates between source and destination to demonstrate that nothing was lost or duplicated in transit. Counts are the cheap version; sums of a monetary column are the version finance will accept. It is unglamorous, and it is the only control that actually catches a silently dropped batch, since every intermediate step reports success on the rows it did see.