Worked on the com-lihaoyi/mill repository to enhance both reliability and tooling management within the build system. Focused on backend development using Scala and Python, the work included refactoring error reporting to centralize path handling through the existing Path constructor, which reduced code duplication and improved maintainability. Additionally, delivered a feature that exposed the virtual environment’s binary directory via the PythonModule, enabling Mill to manage Python tools more consistently and reducing manual configuration for users. These changes streamlined debugging, improved code clarity, and laid the foundation for more reliable Python tool usage across Mill-based projects and build environments.