Designs and executes manual and automated testing for web, API, mobile, and multi-platform applications. Develops risk-based test strategies, test plans, reusable test cases, and Selenium UI automation. Performs functional, regression, smoke, and accessibility testing; investigates logs and browser behavior; documents and tracks defects through resolution. Collaborates with product and development teams in a SAFe Agile Scrum environment and maintains automated test reliability across environments.