The end-to-end data quality validation must combine data contract and business rules validation. A lot has been said about data contracts. They should define the structure and provide proof of validating data to meet constraints. In theory, if you receive data with a defined data contract, you should trust its validity since it has been tested. There is one issue with this belief. You don't want to receive data that is affected by any data quality issue, but the issues could be very subtle. Perhaps a data steward established a rule requiring at least 1000 records per weekday in the transactions table. What if there were no records for a bank holiday? The rule for validating the daily count of transactions is a typical business rule that data stewards should validate. Those types of tests are very valuable because they serve the primary purpose of data quality - to ensure the data is usable for its purpose. However, they should not break the data delivery when they are incorrectly defined. Here comes the real difference between data contracts and business rules. ⚡ Data contracts ensure that the data is in the correct format so it can be ingested without any transformations, filtering out corrupted records, or enriching data to add missing values. ⚡ Business rules validate that the data is usable for various business processes where the data is used. They can fail, but any issue should trigger an investigation. By understanding the difference, we can examine the end-to-end data quality process in data products, the perfect architecture. 👉 Data suppliers should validate that the data they share is not corrupted. The data consumer can revalidate the data only when the data supplier cannot be trusted. 👉 The data platform should reevaluate business rules defined by data stewards. 👉 If the data product shares any datasets with downstream data consumers, it should define a data contract that is validated on published data. #dataquality #datagovernance #dataengineering
Piotr Czarnas Clear distinction. Data contracts keep the pipes clean; business rules ensure the water is drinkable. Too often, teams conflate the two and either block delivery with poorly set thresholds or overlook subtle issues that break trust. The strongest data quality frameworks treat contracts and business rules as complementary, structural integrity plus business usability.
Great point, Piotr! I’ve come across situations where volumetric rules were too specific and seasonal in transactional tables. The rules defined in the contract didn’t cover all the variations that could occur with data volumes across different periods. I believe that with AI we’ll be able to validate and manage these rules more effectively, both from the business and technical perspectives.
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1wPiotr Czarnas Thanks for sharing Strong governance and clear ownership are just as critical as contracts and rules without accountability, even the best validations will fail.