Developed a BitwiseGCD utility for the Hardvan/Java repository, implementing Stein’s algorithm to efficiently compute the greatest common divisor for int, long, and BigInteger types. The solution focused on algorithm implementation and bit manipulation in Java, with careful handling of edge cases such as zero values and Long.MIN_VALUE to ensure correctness across all numeric types. Comprehensive unit tests were written to validate the implementation against a wide range of scenarios, enhancing reliability for gcd-heavy numeric utilities. This work improved runtime performance and correctness guarantees, demonstrating a methodical approach to both algorithmic depth and robust software engineering practices.