Ruff is an extremely fast Python linter and code formatter, written in Rust. With Ruff, projects can replace dozens of static analysis tools with a single dependency, all while executing 10x, 100x, or even 1000x faster.

Over the past year, Ruff has grown to millions of downloads per month, and now powers static analysis for the largest projects in the Python ecosystem, including NumPy, Pandas, PyTorch, LangChain, and more.

This talk will open with a brief overview of Ruff’s functionality before diving into its internals, with a focus on performance. In particular, we’ll look to answer the question: what does it take to build a developer tool that’s orders of magnitude faster than the alternatives?

Our exploration will be grounded in specific optimizations and design decisions that make Ruff fast. Along the way, we’ll also explore the broader tradeoffs that come with building developer tools for Python, in Rust.

Although Ruff is written in Rust, no Rust knowledge is required. Instead, this talk is aimed at those interested in building performant developer tools for any domain, in any language.