Principal Software Engineer - C++ (Networking)

We are part of the Windows Servicing and Delivery (WSD) organization in the Windows + Devices (W+D) division. Our mission is to keep customers protected and productive by delivering a seamless and timely servicing experience across supported and future versions of Windows.

The Customer Focused Engineering (CFE) team within WSD is seeking highly motivated Principal Software Engineers to support this mission. In this role, you will work on Networking components, focusing on maintaining, securing, and improving existing platform capabilities.

Responsibilities

• Provide technical leadership for complex networking components across Windows Client and Windows Server (e.g., TCP/IP stack, DNS, DHCP, VPN, NDIS, filtering platforms, or distributed networking services).
• Drive architecture, design reviews, and invariant-based engineering to ensure security, reliability, and performance at global scale.
• Lead the design and implementation of high-impact features, security fixes, and platform hardening, including variant enumeration and regression prevention.
• Own end-to-end engineering quality,from design and code to validation, deployment, and long-term maintainability.
• Partner closely with security teams, Azure, and Redmond counterparts to align on roadmap, risk mitigation, and cross-platform dependencies.
• Diagnose and resolve complex customer issues and live-site incidents, balancing short-term mitigations with long-term fixes.
• Mentor senior engineers and raise the technical bar through code reviews, design discussions, and engineering best practices.
• Influence engineering processes, tooling, and testing strategies to improve efficiency, correctness, and confidence at scale.

Qualifications Required Qualifications:

• 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.
• Strong expertise in networking fundamentals and protocols, such as TCP/IP, UDP, DNS, DHCP, routing, VPNs, or network security.
• Proven experience designing and debugging low-level, performance-critical, and concurrent systems.
• Demonstrated ability to lead technical design discussions and influence architecture across teams.
• Experience with security engineering, including threat modeling, invariants, and regression risk analysis.
• Strong problem-solving skills and the ability to reason about ambiguous, high-impact technical challenges.

Preferred Qualifications:

• Prior ownership of customer-facing or platform-critical components used at large scale.
• Familiarity with cloud-connected or hybrid networking scenarios.
• Experience driving quality through advanced testing, fuzzing, fault injection, or validation frameworks.
• Ability to collaborate across geographies and influence without direct authority.