During June 2025, Donghwan Kim developed foundational algorithm documentation and feature drafts for the krafton-jungle/KJ-DS-BOOK-9-303 and KJ-ALGO-BOOK-9-303 repositories. He focused on clarifying Priority Queue concepts and implementing a greedy meeting room allocation algorithm, providing detailed problem statements, input/output formats, and Python code solutions. His work emphasized algorithm design, data structures, and documentation, establishing a reusable drafting pattern to improve consistency across projects. By structuring actionable documentation in Markdown and Python, Donghwan enhanced maintainability and onboarding readiness, laying groundwork for future development while demonstrating depth in both technical explanation and practical implementation of core algorithmic concepts.