WheelWizard is a cross-platform desktop application (Windows, Linux, macOS) built with Avalonia and .NET that serves as a comprehensive mod manager, Mii editor, and game launcher for Mario Kart Wii. It integrates deeply with the Dolphin emulator and the WiiCompiled (Recomp) native PC port, providing a unified interface for managing game modifications, custom distributions (Retro Rewind), and online community features (room browser, leaderboard, player profiles). The application handles complex binary Wii data formats, including Mii character serialization, game save files (rksys.dat), and disc image parsing. The architecture is modular, employing dependency injection extensively to separate concerns between the UI (Avalonia views), business logic (feature modules), and data access (external APIs, local filesystem). It features a sophisticated real-time 3D Mii rendering engine using OpenGL and a custom native library (FFL), complete with a keyframe-based animation system for character expressions and idle behaviors. The codebase demonstrates high craftsmanship in its error handling (OperationResult pattern), caching strategies (MiiHeadStore), and cross-platform process management. While primarily an application, it contains significant data engineering components, such as binary format parsers for Wii archives (U8, Yaz0, BRSAR), patch conversion pipelines, and game baseline analysis. The project is actively maintained with a comprehensive test suite, modern dependency management, and a strong focus on code quality, making it a valuable reference for developers working on game tooling, cross-platform desktop applications, or complex UI systems.