During May 2025, Michael Dewart focused on enhancing fixed-point arithmetic reliability in the google/xls repository. He refactored the fixed_point::sub function to correctly handle bit growth during subtraction, introducing an overlap check to determine when an extra bit is required. This update addressed edge cases such as overflow and non-overlapping operands, with expanded test coverage to validate numerical correctness. Working primarily in DSLX and XLS Assembly, Michael applied rigorous testing practices to ensure robust compiler behavior. His work improved the accuracy of fixed-point operations, reducing downstream risk for analytics and formulas that depend on precise arithmetic in the codebase.