Principal Software Engineer

We are looking for a Principal Software Engineer to join the Special Projects and Resources Team (SPARTANs) in M365 Core - Substrate . SPARTANs tackle strategic projects and hard problems across M365 Core that remove agility and modernization barriers for engineers across Substrate.

Substrate is the data and intelligence platform that underpins Microsoft 365, enabling partner teams to build, run, and modernize compliant, reliable services on a global scale. SPARTANs exist so the organization can move faster and make greater impact: we stand up outcome-oriented missions that unblock critical programs in modernization, resilience, cost optimization, compliance, and developer productivity. We are an organization dedicated to serving others, always striving to make a positive impact across teams and the broader community. 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.

Take on problems where the requirements, ownership, and sometimes the root cause are all unsettled. You build a working model of an unfamiliar codebase quickly, form a defensible hypothesis, and convert open-ended asks into scoped projects with clear success criteria.   Own the technical outcome of high-visibility projects from problem framing through deployment and measured impact. You set the bar for clean, testable, observable code, and you leave reusable patterns, documentation, and playbooks behind, so the gain does not decay after we move on.  Build the coalitions the work depends on. You align partner teams who do not report to you, negotiate dependencies and sequencing, and land changes across repositories and service boundaries you do not own. You represent the technical position credibly to executives and to the engineers who will live with the design.  Exercise strong judgement. Decide what to build, what to defer, and what to stop. You weigh reliability, cost, compliance, and time-to-impact under incomplete information, make the call, state the tradeoff explicitly, and revisit it when the evidence changes.  Diagnose and fix latency, scale, and cost problems in always-on distributed services; improve resilience, observability, and incident readiness; and serve as a Designated Responsible Individual across products where the engagement calls for it.  Grow the engineering community. Mentor senior and principal engineers, review designs across the organization, and develop in others the techniques you use to ramp fast and reason well.  You model a growth mindset that treats mistakes as a source of more reliable engineering.

A track record of technical leadership on complex distributed systems, delivered through influence rather than authority.   Depth in design and coding in C#, Java, C++, Rust, or a comparable language, with a tested approach for gaining expertise and confidence in unfamiliar codebases.   Solid distributed systems fundamentals: high-scale, low-latency, always-on services that are inexpensive to operate.   Demonstrated performance engineering experience, including diagnosing and fixing performance and cost problems in production.   Excellent cross-group influence and crisp written and verbal communication, including the ability to tell the story of impact to executive audiences with evidence.

Required 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.   Other Requirements:  Ability to meet