That quite deepnds on the business. Some of our data scenario are super complex (thousands of datapoints, where one influence the others depending on how they h

That quite deepnds on the business. Some of our data scenario are super complex (thousands of datapoints, where one influence the others depending on how they happen in time, depending on manual intervention, things that happen here and there). Because of that, the usual tools to write your business logic fall short on the testing part. They're good at writing/maintaining simple rules, versioning them, but when a time dimension is crucial, then well, it's not that good anymore.