Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for detecting system errors. One of the methods includes collecting an event log for the execution that identifies automated interactions with the application performed by an application testing agent; storing the event log in one or more content storage devices; storing event tracking data captured by a third party system during the automated interaction; comparing the first parameter types with the second parameter types to determine whether expected parameter types from the first parameter types are included in the second parameter types; comparing the corresponding first parameter values with the corresponding second parameter values for the same parameter type to determine whether the corresponding values are the same; and detecting a software error in one or more of the application, the third party system, or the event collection apparatus.