Ben Crabbe developed a bidirectional extrusion and revolution feature for the KittyCAD/modeling-app, expanding its modeling capabilities to support symmetric and opposite-direction operations through new parameter controls. He handled the full engineering cycle, from designing the feature to implementing it in JavaScript and Rust, and updating the documentation and examples to streamline user onboarding. By focusing on CAD and geometry principles, Ben ensured that the new functionality reduced design iteration time and clarified complex shape creation for users. His work demonstrated depth by integrating both technical implementation and user-facing materials within a single repository, reflecting a comprehensive approach to software engineering.