During a two-month period, Doin focused on enhancing technical documentation for the hoodong/2025-2-Sensor repository, targeting photonics sensors and industrial sensor products. Doin authored and updated Markdown-based documents such as 포토인터럽트.md, InGaAs_포토다이오드.md, and TMR.md, standardizing references and clarifying sensor operation, specifications, and integration details. The work emphasized technical writing and documentation structuring, improving onboarding and reducing support needs by providing a single, authoritative source of truth. Through disciplined version control and audience-aware content, Doin enabled faster adoption and cross-team alignment, demonstrating depth in documentation practices and a strong command of Markdown and technical communication.