Worked on the microsoftgraph/microsoft-graph-explorer-v4 repository to uplift test automation and improve code quality by enhancing unit testing coverage and introducing robust test utilities. Leveraged React, Redux, and TypeScript to expand the testing infrastructure, achieving approximately 95% coverage across all modules with nearly 1,900 tests in 197 suites. Addressed TypeScript build errors and stabilized the test and build environment by resolving spec failures and updating configuration files. Integrated new development dependencies and centralized mocking utilities to streamline testing. This work established a strong foundation for faster feedback cycles and safer refactoring, supporting ongoing quality and maintainability of the codebase.