In January 2026, Mict Tseng developed an Acos operation kernel for the FlagGems repository, expanding the library’s mathematical functionality to include inverse cosine support. The implementation involved creating a dedicated kernel using Python, with careful attention to mathematical accuracy and performance optimization. Mict also designed a comprehensive test suite to validate the new operation, ensuring reliability for downstream users and reducing integration risk. The work demonstrated a methodical approach to both feature development and testing, leveraging skills in mathematics and software validation. This contribution deepened the core capabilities of FlagGems for users requiring advanced mathematical operations in Python environments.