Worked on the nodejs/node repository to enhance the reliability and stability of HTTP trailer-related tests, focusing on backend engineering improvements rather than user-facing features. Addressed a longstanding issue by replacing deprecated regular expression assertions in the test suite, which improved compatibility and reduced flaky test behavior. This change led to more predictable and faster continuous integration feedback, directly benefiting the development workflow. Collaborated closely with multiple maintainers through comprehensive code reviews to ensure the maintainability and quality of the solution. Utilized JavaScript and Node.js, applying strong testing practices to stabilize the test suite and improve overall CI health for the project.