During December 2024, this developer focused on restructuring and cleaning up documentation within the geolonia/handbook.geolonia.com repository. They reorganized the directory structure by renaming and removing outdated folders, such as consolidating 営業 to 営業部 and deleting obsolete Marketing references, to improve clarity and navigation. Using Markdown and documentation management skills, they implemented targeted changes that enhanced the maintainability and discoverability of the handbook. The work prioritized minimal risk, introducing no new bugs, and resulted in a more streamlined onboarding process for contributors. Overall, the depth of the changes addressed both immediate organizational needs and long-term documentation governance.