About this role
Principal Software Engineer
United States, Washington, Redmond
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Job description
Company and benefits
Job number
200063835
Date posted
Oct 28, 2026
Work site
3 days / week in-office
Travel
Less than 25%
Profession
Software Engineering
Discipline
Software Engineering
Role type
Individual Contributor
Employment type
Full-Time
Overview
Microsoft 365 Copilot is a groundbreaking productivity tool that leverages the power of large language models, user data, Microsoft Graph, and the web to drive unparalleled creativity and productivity. At the heart of this innovation is the Agent platform, which designs and operates the agent runtime, integrations across M365 apps, and platform to build features that flow consistently to Flagship, 1P, and 3P agents. Our team is building a modular, event‑driven platform that raises agility, reliability, and composability for every Copilot experience.
We are looking for a Principal Software Engineer to help us deliver the next generation of the Agent Platform. You will design, develop, and harden core platform capabilities, real‑time multimodal orchestration, long‑running task durability, and self‑serve partner tooling to unlock safe, rapid innovation across the ecosystem.
As a Principal Software Engineer, you will be responsible for designing, developing, and delivering innovative platform services. You’ll code, debug, test, and troubleshoot production systems that other agents depend on; contribute to safe deployment practices and flighting; build robust telemetry and evals; and collaborate with partner teams to ship features once and light them up everywhere.
In this role, you are expected to have a deep understanding of distributed systems and apply software engineering principles to create high‑quality, observable, and reliable services. You will work closely with other engineers and PMs to ensure our platform meets partner and user needs, adheres to M365 Core engineering standards, and is delivered with guardrails that protect reliability and customer trust.
You will have the opportunity to grow your skills and take on new challenges—ranging from runtime/orchestration and real‑time multimodal to API/protocol design and developer experience while operating at the core of M365 where your work scales across Outlook, Teams, Word, Excel, PowerPoint, and more. Join us and help build the platform that powers the next generation of Copilot agents.
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.
Responsibilities
- Guides engineers within and across teams to produce extensible, maintainable, well‑tested, secure, and performant code that adheres to design specifications.
- Partners with appropriate stakeholders to determine user requirements for one or more complex scenarios.
- Provides technical leadership in identifying dependencies and developing design documents for a product, application, service, or platform.
- Leads by example and mentors others to produce high‑quality code used across the company, promoting engineering excellence and long‑term maintainability.
- Leverages deep subject‑matter expertise of cross‑product features to collaborate with stakeholders and lead multiple products’ project plans, release plans, and w