A method of regression testing a software application in an execution environment is disclosed. The software application interacts with a data storage and is run a first time. While running the software application for the first time, interactions of the software application with the data storage are monitored. Also while running the software application for the first time, first output data written from the software application to the data storage are recorded, and input data received by the software application from the data storage are recorded. The software application is run a second time after the first time. While running the software application the second time, when the software application calls for data from the data storage, at least a portion of the recorded input data is provided to the software application, and, when the software application writes data to the data storage, second output data written by the software application are recorded. The second output data are compared with the first output data to evaluate whether the software application has passed the regression test.