Jihyeok Park enhanced the CI/CD infrastructure for the tc39/ecma262 and tc39/test262 repositories by upgrading and standardizing the ESMeta static type-checking tool across workflows. Using YAML and version control best practices, Jihyeok ensured that each workflow referenced precise commit hashes, enabling reproducible and deterministic type-checking results. The upgrades, delivered through build automation and DevOps methodologies, improved type-checking accuracy and reduced the risk of regressions during pull request validation. By aligning tool versions across repositories, Jihyeok fostered consistent developer experience and earlier detection of type-related issues, demonstrating a methodical approach to maintaining high-quality, reliable continuous integration pipelines.