2025-12 CTStudyGroup/BOJ: Key features delivered to enhance problem-solving capabilities and educational tooling. - Two-Array Target Sum Count Calculator implemented to count ways to reach a target sum using two arrays and their combinations, enabling scalable practice and evaluation. - Two-Ended Character Sorting Algorithm implemented to produce ordered output based on bidirectional comparisons, useful for advanced string manipulation tasks. No major bugs fixed within the provided scope. Overall impact: strengthens problem-solving toolkit, improves accuracy and efficiency of challenge solvers, and supports future repo growth. Technologies/skills demonstrated: algorithm design (two-pointer technique, combinatorial counting), array manipulation, code readability, and commit-level traceability.

November 2025: Key features delivered across CTStudyGroup/BOJ focused on algorithmic efficiency, correctness, and maintainability, enabling business value through cost-aware sorting, configuration exploration, and reliable path computations. Delivered three core features with traceable commits, supporting scalable future work and improved user outcomes: cost-optimized sorting, valid parentheses configurations exploration, and ladder path correctness.