Worked on enhancing the Percy CLI repository by developing new diagnostics features focused on reliability and security. Introduced Quick Mode and Auto-Doctor, enabling faster environment checks and automated remediation for build failures. The approach included adding authentication, configuration, and CI environment variable checks, as well as improving orchestration and reporting within the diagnostics workflow. Security was strengthened by sanitizing HTTP error messages and preventing sensitive environment variable leakage. Comprehensive Jasmine test coverage was expanded, with deterministic mocks ensuring robust validation. Leveraged JavaScript and Node.js within a full stack development context, emphasizing CI/CD best practices and cross-platform compatibility improvements.