Worked on the cloudflare/playwright-mcp repository to address compatibility challenges during the project’s migration from CommonJS to ECMAScript Modules (ESM). Focused on stabilizing the transition, the developer implemented a CommonJS compatibility layer by recreating the 'require' function at runtime using Node.js’s createRequire utility. This approach allowed legacy modules dependent on CommonJS to function correctly within the new ESM environment, preventing runtime errors such as 'require is not defined.' The work, carried out in TypeScript and Node.js, enhanced project stability and reduced production risk, enabling a smoother and safer migration path between module systems without introducing new features.