What are the main use-cases for data tests?

On a technical level, data tests will help you to detect early that your data is broken. Furthermore, a data test can act as a gatekeeper before a subsequent data job is triggered.

On the other hand, data tests will help you to detect drastic changes in your metrics & KPIs. In this case, a data test will be combined with an alert. Let's say your avg. daily gross revenue is ~ 25.000 $ and you set up a data test incl. alert that daily gross revenue should be > 24.999 $. In case the gross revenue of a specific day falls below this threshould, you'll received a notification that your gross revenue has dropped below the daily target for previous day.