Austin focused on enhancing the reliability of geometric modeling within the KittyCAD/modeling-app repository by developing comprehensive test coverage for KCL Geometric Boolean Operations. He implemented simulation test modules in Rust to rigorously validate subtract_self, subtract_self_multiple_tools, and union_self operations, ensuring robust parsing, unparsing, and execution paths. By targeting these core Boolean operations, Austin’s work strengthened regression protection for the KCL library, reducing risk during future refactors and supporting safer, faster feature development. His approach emphasized thorough testing and code stability, leveraging skills in CAD, geometric modeling, and Rust to deliver a deeper level of quality assurance for the project.