What are the Testing Tiers® software tester ranking levels? The Testing Tiers® software tester ranking levels are provided by AT*SQA to help companies and managers compare software testers when considering software testing jobs and promotions. Only ISTQB certifications from AT*SQA and ASTQB are included in Testing Tiers® so it is important that you register for your ISTQB exams through AT*SQA or through ASTQB. To see the Testing Tiers® ranking for a software tester, click on that tester’s “Profile” in the Official U.S. List of Certified Software Testers™. Learn More About Testing Tiers® Software Tester Ranking Levels Testing Tiers® is a trademark of AT*SQA, the official ISTQB exam provider globally for ASTQB.