In our company , we had an intersting discussion on whether SIT testers should have access to the design docs and the database for a web based application? Should they be actually looking for data in the database or just check if the requirements are met by testing the GUI - If everything works on the GUI as expected , does it mean the backend is correct ? Backend Testing according to one was Unit testing to be done by the developers . If SIT testing is only GUI testing , then what is the difference between SIT and UAT testing ? There were different opinions - but I would like to know what is the text book answer of the question - Should SIT testers be doing backend testing on a web based application ?