Sr. Software Engineer--M365 Routing Fabric Team

We are looking for a highly motivated and technically strong Software Engineer who is passionate about building intelligent, scalable, and resilient systems at the heart of Microsoft 365’s infrastructure. You will join the Substrate Unified Fabric team, which is driving the modernization of cloud routing through RouteResolutionService—a core platform component designed to deliver highly accurate, efficient, and secure routing for Microsoft 365 workloads across global infrastructure.

The SURF (Substrate Unified Routing Fabric) team is responsible for the Substrate Routing Platform, which routes trillions of HTTP requests daily with industry-leading accuracy and minimal latency. With the MIRA (M365 Integrated Routing Architecture) initiative, SURF now handles traffic for major M365 workloads like Teams and SharePoint Online, providing enhanced routing, resilience, and security. The team is known for technical excellence, a culture of innovation, and a commitment to operational impact at massive 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.

Design and implement features in RouteResolutionService to support different scenarios in M365 including Copilot.  Build distributed, highly available and resilient systems. Work with services spanning thousands of servers, doing tens of billions of transactions and serving hundreds of millions of users. Drive technical excellence through code reviews, architecture design, and mentoring of other engineers. Build Agentic-loop to accelerate development Qualifications Required Qualifications: Bachelor'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 Requirements: Ability 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 years thereafter.

Master'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 Bachelor'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 equivalent experience.  3+ years of industry experience in service development, successfully shipping services through multiple releases.  Solid understanding of distributed systems, and AI/ML-driven decision systems. Passion for quality and proven record of delivering excellent results under challenging schedule to work on one of the largest distributed systems in the world.    Proficiency in Rust is a plus. Real-world experience developing large scale online services with robust performance, resiliency, telemetry, and security.   Solid collaboration skills with the ability to work in a dynamic/agile environment.    A passion for improving engineering practices and producing high quality software.   Self-motivated and customer focused.   Excellent communication and collaboration skills, with a track record of working across organizational boundaries.  This position will be open for a minimum of 5 days, with applications accepted on an ongoing