Principal Software Engineer

Lead architecture, design, and implementation for complex Substrate Transport modernization work, including cloud-native platform capabilities, and integration with Exchange Online and broader M365 service dependencies. Partner with product managers, technical program managers, security/privacy experts, customer escalation teams, and partner engineering teams to determine requirements, validate feasibility, and translate ambiguous customer and service needs into clear technical direction and executable milestones. Own and broker cross-team architecture decisions across upstream and downstream dependencies, ensuring designs meet performance, scalability, resiliency, disaster-recovery, cost, security, privacy, compliance, and accessibility expectations. Lead by example in producing extensible, maintainable, well-tested, secure, performant code and reviewing code and test code for diagnosability, reliability, maintainability, security risks, compliance issues, and appropriate test coverage. Define and use the right optics, quality metrics, telemetry, dashboards, and feedback loops to guide technical decisions, measure customer value, identify risks early, and improve service health and engineering outcomes. Drive safe-change practices including feature flags, flighting, experimentation, deployment automation, rollback strategies, production-like validation, and secure dependency management to minimize customer impact and accelerate recovery. Lead live-site engineering for a globally distributed service: act as a designated responsible individual when needed, improve troubleshooting guides, reduce recurring incidents, drive retrospectives and repair items, and strengthen monitoring and operational readiness. Apply AI-native development practices responsibly, including appropriate controls over AI-generated requirements, designs, code, tests, and operational assets; evaluate AI tools and practices that improve engineering productivity and quality. Bachelor's Degree in Computer Science or related technical field AND technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python Experience leading architecture and delivery for large-scale distributed cloud services, high-throughput messaging platforms, email transport, service-to-service communications, or comparable mission-critical infrastructure. Experience driving multi-year technical initiatives across teams or organizations, including dependency alignment, architecture tradeoffs, measurable milestones, and sustained delivery through ambiguity. Experience with AI-assisted engineering workflows, with demonstrated judgment around Responsible AI, validation, controls, and quality ownership for AI-generated assets. These requirements include but are not limited to the following specialized security screenings: Master's Degree in Computer Science or related technical field AND 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 technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python OR equivalent experience. Deep expertise in reliability engineering, observability, incident prevention, production debugging, safe deployment, performance optimization, and operational excellence for global cloud services. Experience building secure and compliant systems, including threat modeling, least-privilege operations, privacy-aware telemetry, auditability, secure coding practices, and integration with security monitoring and response processes. Experience applying data-driven decision making to product and platform engineering, including defining metrics, interpreting production signals, and using customer and service data to guide design and prioritization. Demonstrated ability to mentor senior engineers, influence technical direction without direct authority, communicate clearly with executives and partner teams, and create an inclusive culture that enables others to do their best work.