Developed a comprehensive testing toolkit for the Host Reach Tracker within the facebook/fboss repository, focusing on enhancing test isolation and reliability for host reach path validation. The work involved designing and implementing a standalone C++ binary, hrt_test_rig, which includes a command-line interface for dynamic route and plane management. Leveraging Thrift for service definition and backend communication, the developer introduced a simulated FSDB server to enable end-to-end testing without requiring real FSDB deployments. Additionally, they addressed compatibility issues by capping threads in the FsdbTestServer, ensuring support for multiple FSDB servers on a single host and improving overall test coverage.