Execute manual test plans, test cases, and test scripts for frontend and backend systems. Perform functional, smoke, regression, and exploratory testing across mobile and web platforms. Identify, document, and track software defects using tools such as JIRA or TestRail. Run existing automated test scripts and analyze output. Collaborate with QA Engineers to identify areas for automation coverage expansion. Contribute to test data setup and validation of test environments. Validate bug fixes and assess regression impact before releases. Work closely with developers and product managers to clarify requirements. Participate in Agile ceremonies including sprint planning, stand-ups, and QA reviews. Maintain up-to-date documentation of test results and report test coverage and defect trends.