Principal Software Engineer

Microsoft
United States, Washington, Redmond
Aug 20, 2025
OverviewWithin the Developer Division, the Languages, Runtimes, and Compilers Group at Microsoft is responsible for best-in-class support for C++, Java, .NET (C#, Visual Basic, and F#), Python, Rust, and Go. Developer Division in CoreAI believes that software development is rapidly evolving in the age of Artificial Intelligence. We are building the future of platforms and tools for this new era-and we are looking for developers who are not only early adopters of AI-powered development tools, but who are also actively exploring how Large Language Models (LLMs) can enhance their effectiveness and impact. Be a part of a team that values collaboration and the idea of working better together. Come and help us define the language, optimize the compiler and runtime, and build tools that empower developers worldwide to build great software. If you are ready to take on your next big challenge, join us to help redefine the future of developer tools. We are building the next generation of Python development experiences, combining state-of-the-art language services with AI-powered assistance. Our team owns pylance, the leading Python language server, and debugpy, the Python debugger behind Visual Studio Code. We are now pushing further into the age of AI: integrating with GitHub Copilot, improving agent chat context with real-time diagnostic and linting insights, developing Model Context Protocol (MCP) tools, and reimagining debugging and software development in a world where AI and humans collaborate closely. We are looking for a Principal Software Engineer to lead and contribute at the forefront of this transformation. This is a high-impact role where you will work on cutting-edge problems in language tooling, debugging, static analysis, and AI-assisted development - and shape the experience of millions of Python developers worldwide. You will engage deeply with the Python community, the AI developer tools ecosystem, and internal partners across DevDiv, Office, Azure, and GitHub. You will contribute code, influence vision and strategy, and mentor engineers to deliver world-class tools that make developers more productive and creative than ever before. ResponsibilitiesLead the design and implementation of core features in Pylance, debugpy, and related tools.Collaborate with AI teams to enhance Copilot chat and agent experiences with rich language and debugging context.Invent and prototype new paradigms for debugging and diagnostics in the AI era.Define and deliver Model Context Protocol (MCP) integrations for Python and multi-language workflows.Drive deep customer engagement through GitHub, feedback channels, and direct interactions to gather insights and represent the Python developer's voice.Mentor engineers and help shape the vision for the Python tools team and its role in the broader Microsoft Artificial Intelligence & developer ecosystem.MS Culture & Values: Embody our Culture and Values.