Principal Software Engineer - M365

Microsoft 365 and Copilot operate at extraordinary scale, and behind them is Substrate & Work IQ (SWIQ), the trusted data and intelligence foundation that helps Microsoft understand, operate, and continuously improve some of its largest cloud services. SWIQ connects product experiences, infrastructure, operations, and business outcomes to power service health, operational excellence, business insights, and AI-driven decision-making. The SWIQ Performance Team is looking for a Principal Software Engineer to tackle some of the most challenging performance and efficiency problems across Microsoft 365 and Copilot. Our mission is to deliver fast, reliable, and efficient experiences at global scale while building the intelligence and engineering systems needed to sustain continued growth. This is not a narrowly scoped performance role. You will work across software, infrastructure, data, and AI to identify and solve high-leverage problems in latency, scalability, reliability, resource efficiency, telemetry, cost optimization, infrastructure demand, benchmarking, and platform health. You will influence where we optimize software, evolve architecture, change operating models, and invest in the platform. Success requires more than technical depth. You will need to navigate ambiguity, connect signals across complex systems, understand customer and business impact, and turn insights into clear engineering decisions and measurable outcomes. This is also an AI-first engineering role. You will use agents, automation, AIOps, AI-driven analysis, evaluation systems, and rapid prototyping to reason across telemetry, explore tradeoffs, identify opportunities, and accelerate decisions. Just as importantly, you will help shape how engineering itself evolves, building more scalable and AI-forward ways to understand and operate complex systems. You will partner with engineering and product leaders, architects, data scientists, finance, service owners, and teams across Microsoft 365. The role offers broad visibility and influence for an engineering leader who wants to shape systems, drive cross-organizational execution, and make a measurable difference at Microsoft 365 and Copilot scale. 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.

Set technical direction and architecture for performance, scalability, reliability, and strategic efficiency across Microsoft 365 and Copilot, connecting customer experience, platform health, resource consumption, and long-term system evolution. Own complex, ambiguous problems end to end , from deep technical investigation and architecture through implementation, production rollout, measurement, and sustained results, especially for problems spanning multiple services and organizations. Lead cross-organizational engineering efforts and architectural decisions , balancing performance, reliability, scalability, resource efficiency, operational complexity, engineering velocity, and customer impact while influencing teams beyond direct ownership. Build reusable platform capabilities and technical leverage , turning recurring problems and successful solutions into shared architectures, frameworks, APIs, automation, tools, and engineering patterns that benefit multiple teams. Use deep systems understanding and data to drive engineering decisions , applying telemetry, profiling, benchmarking, experimentation, prototypes, evaluation frameworks, and production signals to identify root causes, quantify opportunities, and make informed technical tradeoffs. Lead the design and implementation of high-impact engineering solutions across latency reduction, infrastructure demand