Pybites Podcast #199: Charlie Marsh on ty, uv, and the Python tooling renaissance
Aug 6, 2025
Charlie Marsh, who builds high-performance Python tooling at Astral, discusses the innovative ty tool that transforms Python type checking. He shares insights into ty's lightning-fast incremental analysis and improved diagnostics, drawing inspiration from Rust. Marsh also talks about Astral's collaboration with Meta and NVIDIA to tackle broader ecosystem challenges. He highlights the importance of user-friendly design in tooling and the evolution from Ruff to ty, aiming to enhance developer experience while minimizing false positives in coding.
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Why UV Added Its Own Build System
- Astral built an integrated build system inside UV to avoid confusing beginners with external build tools.
- The UV build feature reduces friction by offering a simpler path for common Python packaging use cases.
UV Prototype For GPU‑Aware Installs
- Astral prototyped a UV installer that detects GPU type and installs the correct PyTorch wheel as a proof of concept.
- That prototype coordinated with Meta and NVIDIA and might influence future packaging standards.
Single Tool For Check And LSP
- Ty is both a fast command-line type checker and a language server designed to give consistent analysis across CI and editor workflows.
- Astral focuses on speed, diagnostics, and scaling to large projects to improve developer experience.