Worked on the Apache Shiro repository, focusing on maintaining and improving security-critical hashing logic within the DefaultHashService component. Addressed a bug by removing a redundant Optional presence check, opting instead to retrieve the HashSpi instance directly after confirming its presence. This approach reduced unnecessary exception handling and simplified the control flow, enhancing both maintainability and reliability in a frequently used code path. The work was implemented in Java, leveraging expertise in cryptography and software development. All changes were clearly documented to support future audits and reviews, ensuring traceability and clarity for ongoing maintenance of the security-sensitive codebase.