A development studio building critical tooling for the Python ecosystem — in official partnership with python.org to advance the language and its community.
We design, build, and maintain foundational tools that Python developers rely on every day — with a focus on performance, correctness, and seamless integration across the ecosystem.
High-performance command-line interfaces and developer utilities that streamline everyday Python workflows.
Tooling for resolving, installing, and managing Python packages with speed and reliability at scale.
Build pipelines, test runners, and continuous integration infrastructure purpose-built for Python projects.
Code quality tools — linters, formatters, and type checkers — that enforce standards without slowing teams down.
We contribute to and maintain tools across the Python ecosystem, working in concert with python.org to ensure official support and long-term sustainability.
A next-generation dependency resolver for Python packages. Deterministic, fast, and compatible with PyPI metadata standards.
An extensible linting framework with first-class support for type stubs, PEP compliance checks, and auto-fix capabilities.
A parallel build backend for Python projects supporting PEP 517/518, with native C-extension compilation and caching.
Python Extensions is a focused development studio dedicated to the Python programming language and its ecosystem. We work in direct concert with python.org, the Python Software Foundation, and core maintainers to build and sustain official tooling infrastructure.
Our team brings deep expertise in CPython internals, packaging standards, and high-performance systems programming. Every tool we ship is designed to meet the demands of both individual developers and organizations operating Python at scale.
We believe the best developer tools are the ones you never have to think about — they just work, every time, instantly.
Execution speed matters. We profile and optimize relentlessly, leveraging Rust and C where it counts.
PEP-compliant, thoroughly tested, and predictable. No surprises in production.
Everything we build integrates cleanly with the tools Python developers already use.
Transparent development, permissive licensing, and community-driven roadmaps.
Python Extensions operates with the support of and in concert with python.org to deliver official tooling that strengthens the entire Python ecosystem.