Most data quality work ends at a dashboard. Tests run after the load, results are written to a table, a tile turns amber, and everybody agrees that someone should look at it. Nobody does, because looking at it is not anyone's job in particular.
A test with no consequence is documentation. It records an intention about the data and changes nothing about what reaches the warehouse, which means the wrong figure is served either way.
What the consequence actually buys
A contract is a claim about shape, range, freshness and referential integrity, declared beside the data and evaluated on every load. What makes it a contract rather than a report is the clause that fires on breach: the load stops, or a named person is paged.
That reads as severe until you price the alternative. A silent schema change propagates for weeks. Someone reconciles by hand in month three, and the cost is not the fix. It is every decision taken on the wrong figure in between, none of which can now be revisited.
Not every breach should stop a load
Blocking on everything is how a contract gets switched off, usually at two in the morning by whoever is on call. Grade the clauses instead, and be willing to defend the grading.
A null in a joining column blocks, because every downstream figure built on that load would be wrong. A freshness breach on a low-consequence feed pages the owner and lets the load through with the staleness recorded, because stale and labelled beats absent and unexplained.
- Block: uniqueness, referential integrity, nulls in join keys, type changes
- Page: freshness, volume anomalies, distribution shifts that need a person to judge
- Record: everything else, kept so the pattern is already visible when it becomes an incident
The owner is the hard part
The engineering is a day of work. Naming the person the breach wakes takes considerably longer, because it is the moment a producing team discovers that a downstream consumer exists and has expectations of them.
That conversation is the point rather than an obstacle to it. A contract is an agreement between two teams that happens to be enforced in code, and one with a single signatory is a dashboard with better tooling.
