During July 2025, Dongwook Woo developed a core feature for the sopt-makers/sopt-playground-frontend repository, focusing on external account service integration. He implemented a Cloudflare Pages function in TypeScript that rewrites request hostnames to the accounts domain, effectively decoupling account management from the frontend. This approach established a clear separation of concerns, improving both security and scalability for authentication workflows. By leveraging API integration and frontend development skills, Dongwook delivered a reusable integration pattern that supports future external service connections. The work was delivered as a focused commit, reflecting a deep understanding of maintainable, cloud-based authentication architecture and deployment practices.