Principal Software Engineer; Networking Systems

Principal Software Engineer (Networking Systems)

Are you passionate about designing the next generation of networking solutions for AI‑driven and Azure datacenters? Join our team to architect and implement transport and other networking solutions that power Microsoft’s cloud‑scale AI and Azure infrastructure. As a Network Engineer at L65, you will collaborate across hardware, software, and business teams to deliver robust, scalable, and innovative networking solutions.

Microsoft’s mission is to empower every person and every organization on the planet to achieve more. Employees come together with a growth mindset, innovate to empower others, and collaborate to achieve our shared goals. We build on our values of respect, integrity, and accountability to create a culture of inclusion where everyone can thrive at work and beyond. In alignment with our Microsoft values, we are committed to cultivating an inclusive work environment for all employees to positively impact our culture every day.

Join the Strategic Planning and Architecture (SPARC) team within Microsoft’s Azure Hardware Systems and Infrastructure (AHSI) organization, the team behind Microsoft’s expanding Cloud Infrastructure and for powering Microsoft’s “Intelligent Cloud” mission. AHSI is the team behind our expanding cloud infrastructure. We deliver the core infrastructure and foundational technologies for Microsoft’s cloud businesses including Microsoft Azure, Bing, MSN, Office 365, One Drive, Skype, Teams and Xbox Live.

We are seeking a Principle Software Engineer (Networking Systems) to lead the design and development of scalable networking systems, transports, and telemetry frameworks that support Azure’s AI and data center infrastructure.

• Design and implement transport networking architectures to support high‑performance AI workloads and distributed systems.
• Develop and optimize frontend datacenter networking solutions, ensuring seamless connectivity, reliability, and scalability for cloud and AI services.
• Engineer host networking frameworks that enable efficient communication between compute nodes, storage, and accelerators.
• Collaborate with cross‑functional teams (hardware, software, product, and business) to define requirements and deliver integrated solutions.
• Drive adoption of best practices in network observability, diagnostics, and performance optimization.
• Participate in incident response and root cause analysis to ensure live site reliability and continuous improvement.
• Contribute to technical strategy and innovation in AI networking and datacenter connectivity.

• Bachelor’s Degree in Computer Science or related technical field AND 6+ years technical engineering experience with coding in languages including C, C++, C#, Java, JavaScript, or Python OR equivalent experience.
• 5+ years of experience in network engineering, with expertise in transport, datacenter, or host networking.
• 5+ years of experience in networking protocols (TCP/IP, RDMA, Ethernet, Infini Band) and cloud technologies.
• 5+ years of experience with large‑scale distributed systems and AI infrastructure.

• PhD Degree in Computer Science or related technical field.
• Experience with AI/ML workloads and their networking requirements.
• Familiarity with datacenter hardware (switches, NICs, DPUs, accelerators).
• Advanced knowledge of SDN, network virtualization, and automation frameworks.
• Demonstrated ability to drive technical initiatives and mentor engineers.
• Solid programming skills in C, C++, Python, Rust, or similar languages.
• Proven ability to collaborate and communicate across teams.

• Ability to meet Microsoft, customer and/or government security screening…