Worked on the jdx/mise repository to enhance the reliability of install and upgrade processes by addressing issues with fuzzy install requests and stale directory handling. Applied Rust and backend development skills to implement a fix that prevents the creation of literal directories when a concrete version cannot be determined, while preserving support for legitimate short version schemes. Introduced a one-time migration to repair existing broken installs and improved the runtime symlink strategy to self-heal stale directories. Expanded end-to-end and unit test coverage using Rust tooling, resulting in reduced user-facing install failures and more stable upgrade and deployment workflows.