During January 2025, Donghwan Kim developed two in-depth documentation features for the SYSOUT-org/CS-Study repository, focusing on database transactions and normalization. He consolidated complex concepts such as ACID properties, isolation levels, and transaction anomalies, providing clear guidance on MySQL and Spring transaction management. Using Markdown, Donghwan structured the documentation to enhance onboarding and reduce support time, ensuring alignment with repository standards. His work demonstrated a strong grasp of database theory and practical documentation skills, delivering comprehensive resources on normal forms, denormalization, and performance considerations. The depth and clarity of these contributions improved maintainability and knowledge sharing for future developers.