As a part-time QA tester, your job is to test a product to help ensure it's free of defects and errors before it goes into full production. In this role, you may evaluate a product at each stage before launch, collaborate with other testers to execute test cases and scripts, and help isolate any physical or programming issues. Part-time QA testers usually work with larger groups and projects, including stress tests that help evaluate how well a system handles dozens, hundreds, or even thousands of simultaneous users. QA testers usually have full shifts on the days they work, so taking a part-time shift in this field usually means working fewer days per week instead of fewer hours per day.