Product quality assurance and testing strategy

Implement comprehensive quality assurance for product reliability. Testing pyramid: 1. Unit tests (70%): individual component functionality. 2. Integration tests (20%): component interactions. 3. End-to-end tests (10%): full user workflows. Testing types: 1. Functional testing: features work as specified. 2. Performance testing: load, stress, volume testing. 3. Security testing: vulnerability scanning, penetration testing. 4. Usability testing: user experience validation. 5. Accessibility testing: compliance with accessibility standards. QA process: 1. Test planning: define scope, approach, criteria. 2. Test case design: positive and negative scenarios. 3. Test execution: manual and automated testing. 4. Bug reporting: clear reproduction steps, severity classification. 5. Regression testing: ensure new changes don't break existing functionality. Automation strategy: automate repetitive tests, maintain test suite health, balance speed vs. coverage. Tools: Selenium for web testing, Cypress for modern web apps, Postman for API testing. Quality metrics: test coverage, defect density, customer-reported bugs, time-to-detection.