Over two months, Hkamin contributed to the S3J7/Group_12_JavaProject repository by developing lightweight Java utilities focused on validation and practice scenarios. He implemented a parity-checking tool to classify integers and a FizzBuzz-like number printer, both designed for clarity and ease of use. His approach emphasized clean code and maintainability, demonstrated by proactive test scaffolding cleanup and well-documented commit histories. Leveraging Core Java and algorithmic thinking, Hkamin delivered reusable arithmetic helpers and validation utilities that support onboarding and rapid prototyping. The work reflects a focus on foundational engineering, prioritizing reliability, traceability, and practical teaching value in Java development.