Senior Software Engineer/ Principal Software Engineer - Copilot CLI

Senior Software EngineerWithin GitHub and Microsoft CoreAI, the Copilot CLI team builds GitHub's coding agent in the terminal, and the core agent loop that powers agentic experiences across GitHub and Microsoft. Our work spans the full software development lifecycle, with a focus on turning modern AI systems into reliable, production-grade developer tools.We are looking for a Senior Software Engineer to help build a world-class coding agent CLI. This role is for engineers who care deeply about product quality, end-to-end ownership, and the details that separate promising tools from ones developers trust and adopt daily.Our work sits at the intersection of agentic AI systems and high-performance developer tooling. We are particularly interested in candidates with strength in one or more of the following areas:Building, evaluating, and iterating on agentic systems, including tool design, agent loops, benchmarking, and quality optimizationBuilding delightful, high-performance terminal experiences, including terminal UIs, low-level primitives, and systems that feel fast, predictable, and polishedEngineers on this team operate with high autonomy and a strong product mindset. You will own large surface areas end-to-end, partner closely with product and design, and push to continuously raise the quality bar for both the CLI and the underlying agent platform used across GitHub and Microsoft.Microsoft's mission is to empower every person and every organization on the planet to achieve more. As part of GitHub and CoreAI, we build developer tools that materially improve how software is written, reviewed, and shipped, while maintaining a culture of ownership, rigor, and technical excellence.Microsoft's mission is to empower every person and every organization on the planet to achieve more. As employees we come together with a growth mindset, innovate to empower others, and collaborate to realize our shared goals. Each day we build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond.ResponsibilitiesTake ownership of critical product and platform areas of the Copilot CLI and shared agent runtimeSet a high technical and quality bar for agentic systems and developer-facing toolingDesign and ship performant, reliable terminal experiences that developers depend on for daily workUse data, benchmarks, and direct user feedback to guide iteration and investmentCollaborate across org boundaries to enable other teams to build agentic products on top of a shared foundationInfluence architecture, technical direction, and engineering standards beyond your immediate teamQualificationsRequired QualificationsBachelor's Degree in Computer Science or related technical field AND 4+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience.Other RequirementsAbility to meet Microsoft, customer and/or government security screening requirements are required for this role. These requirements include but are not limited to the following specialized security screenings:Microsoft Cloud Background Check: This position will be required to pass the Microsoft Cloud background check upon hire/transfer and every two yearsPreferred Qualifications:Bachelor's Degree in Computer Science or related technical field AND 6+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience.Hands-on experience building and operating generative AI or agentic systems in production, with direct ownership over quality, reliability, and iteration5+ years of experience building and shipping customer-facing developer products, with depth across platform/foundation systems and user-facing experiencesStrong product mindset with a track record of owning ambiguous problem spaces and driving them to high-quality outcomesSolid engineering fundamentals, including systems design, performance, and debugging in complex production environmentsExperience designing, running, and optimizing evaluations for agentic systems, including tools, prompts, and agent loopsExperience building terminal user interfaces (TUIs) or working with low-level terminal primitives is a strong plusExperience contributing to or leading open-source projects at scale is a plus