Jeonghwan worked on the toss/frontend-fundamentals repository, focusing on enhancing the documentation site’s branding by updating the header to display a new logo. Using TypeScript for front-end development and Markdown for documentation, Jeonghwan prepared and integrated new logo assets, renamed the original logo file for clarity, and refined the header configuration to ensure consistent branding across all documentation pages. The work addressed asset management and presentation, resulting in a cleaner and more unified documentation experience. Over the course of one month, Jeonghwan delivered a single feature with no bug fixes, demonstrating a focused approach to documentation and front-end improvements.