Developed two Java-based solutions in the onestone11/kosa-study-tigger repository, focusing on practical problem solving for classroom and operational scenarios. Delivered a coin change calculator that applies a greedy algorithm to minimize coins needed for Japanese yen transactions, emphasizing maintainable code and efficient array manipulation. Also implemented a gym clothes distribution feature that maximizes student participation by handling borrowing logic and edge cases through clear, testable Java code. Both features were designed for quick review and potential reuse, demonstrating proficiency in Java, algorithm design, and basic input/output. The work prioritized business value, scalability, and robust handling of real-world constraints.