Implementations include receiving, by a DDT platform, computer-readable files including test data, the test data including data to execute at least one transaction during testing of a software system that is at least partially hosted by a vendor back-end system, the software system being configured for customer use, providing, by the DDT platform, one or more test scenarios for execution by the software system on the vendor back-end system, the one or more test scenarios including a set of activities to conduct transactions by the software system using at least a portion of the test data, scheduling, by a scheduler of the DDT platform, execution of the one or more test scenarios using a test harness of the DDT platform, receiving, by the DDT platform, test results from the vendor back-end system, and comparing, by the DDT platform, the test results to expected results to provide a comparison as output.