The Principal Software Engineer - HW/SW in Fleet Infrastructure at Microsoft 365 Core Platform will provide technical leadership for the evolution of Substrate's hardware and firmware platforms. This role focuses on shaping New Product Introduction strategy, hardware and firmware health architecture, and live-site reliability. The engineer will collaborate with various teams across Microsoft 365 and Azure infrastructure to define architecture and solve complex infrastructure problems. The position is based in Redmond, Washington, requiring in-office presence at least three days a week.

• 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.
• Ability to meet Microsoft, customer and/or government security screening requirements.
• Master's Degree in Computer Science or related technical field AND 8+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR Bachelor's Degree in Computer Science or related technical field AND 12+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience.
• Experience leading architecture and technical strategy for large-scale distributed systems, cloud infrastructure, or hyperscale service platforms.

• Partner with broad teams to design, develop, validate, debug, and optimize infrastructure software across OS, firmware, fleet health, hardware repair, telemetry, and monitoring areas.
• Define the technical strategy and architecture for New Product Introduction across Microsoft 365 fleet infrastructure.
• Lead hardware and firmware reliability architecture, including health telemetry, diagnostics, failure detection, predictive insights, and remediation automation.
• Drive failure analysis and root cause investigation for critical live-site incidents and implement durable improvements.
• Establish engineering standards, observability patterns, and operational mechanisms that improve fleet availability.
• Evolve M365 substrate infrastructure strategy for AI and agentic workloads across compute, memory, storage, and networking domains.
• Influence cross-organizational technical direction and help teams make durable architecture decisions.
• Mentor early in career engineers.

• Employees at Microsoft are often offered comprehensive, “world-class” benefits—including health and mental-wellness programs, competitive pay with bonuses and stock awards, and retirement/savings options. Time-off and flexibility are common, with generous vacation and holidays, parental and caregiver leave, and flexible work schedules, alongside learning support, employee resource groups, product discounts, and matching-gifts/volunteering programs. Specific benefits can vary by region.