During November 2024, Dung Nguyen developed the core engine for a Battleship game in the d23-java/seabattle repository, focusing on establishing a solid foundation for future enhancements. Using Java and object-oriented programming principles, Dung implemented board initialization, ship placement, turn-based gameplay, and winner determination, all accessible through a command-line interface. The work emphasized clean design and maintainability, with UML-driven commits guiding the architecture and supporting future refactoring. By delivering a production-ready CLI UI and maintaining a clear commit history, Dung ensured the project was well-structured for testing and ongoing development, demonstrating depth in game development and software design.