December 2024 monthly summary for Yorkie repositories. Focused on stabilizing CI/CD and achieving environment parity across codepair and yorkie-js-sdk. Delivered two key updates: (1) CI Node.js Version Standardization for yorkie-team/codepair by adding .nvmrc and updating workflows to read the version from it, reducing local/CI drift; (2) CI/CD Workflow Updates for yorkie-team/yorkie-js-sdk by upgrading GitHub Actions versions to improve reliability, security patches, and compatibility for CI/CD and GitHub Pages deployment. No major bugs were logged this month. Impact: higher build reliability, faster onboarding, and smoother deployments; cross-repo standardization reduces future maintenance. Technologies demonstrated: Node.js version management, GitHub Actions, CI/CD best practices, deployment automation to GitHub Pages.