Radix is a native macOS disk space analysis application built with SwiftUI, Swift concurrency, and deep integration with macOS filesystem APIs (APFS clones, FSEvents, getattrlistbulk). The core scanning engine uses actor-based parallelism with atomic directory summarization, incremental rescanning via FSEvent history, and cancellation-aware sort and layout operations. The app features interactive sunburst and treemap visualizations with viewport pan/zoom, a searchable file browser with sorted tables, discard pile for staged trash operations, cross-snapshot comparison showing file changes over time, and export/import of scan snapshots in a versioned compressed archive format (.radixscan). Architecture follows a clean separation of Models, Services, ViewModels, and Features, with heavy use of dependency injection closures for testability. The codebase includes extensive unit, integration, and benchmark tests (Swift Testing) covering correctness, performance, and concurrency safety. It demonstrates high craftsmanship in file tree storage (compact arena with logical scopes), cancellation patterns, APFS storage accounting, and interactive chart geometry.