Software Engineer II

As a Software Engineer II, you will design and build core transport technologies alongside experts across Windows, Azure, SQL, Security, and Developer Platform. You will work on QUIC and HTTP/3, TLS, congestion control, network acceleration, and the diagnostics and security that make them trustworthy - solving hard problems in performance, reliability, and protocol design. It is a role that deepens your expertise in networking, systems architecture, and distributed systems, with real opportunities for impact across the industry and in open source.

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.

Responsibilities

• Design, implement, and maintain features in core networking components including TCP/IP, MsQuic, and related transport technologies.
• Develop scalable and performant networking capabilities for Windows and Azure platforms.
• Contribute to next-generation transport innovations involving QUIC, TLS, congestion control, network acceleration, and cloud-scale networking.
• Investigate and resolve complex networking, reliability, performance, and security issues across large-scale distributed systems.
• Partner with cross-functional teams to design robust networking APIs and developer experiences.
• Drive improvements in diagnosability, observability, telemetry, and troubleshooting capabilities.
• Contribute to security initiatives including vulnerability remediation, secure protocol design, and transport-layer hardening.
• Participate in architecture reviews, design discussions, code reviews, and engineering excellence initiatives.
• Work closely with global teams across Redmond and IDC to deliver high-quality networking solutions.
• Embody our Culture and Values.

• Bachelor’s Degree in Computer Science or related technical field AND 3+ years technical engineering experience with coding in languages including, but not limited to, C, C++, C#, Java, JavaScript, or Python.
• OR equivalent experience., * Bachelor’s degree in Computer Science, Computer Engineering, Electrical Engineering, or related technical field, or equivalent industry experience.
• 3+ years of software development experience with C/C++ or systems programming languages.
• Solid understanding of operating systems fundamentals including memory management, concurrency, synchronization, and performance optimization.
• Knowledge of networking fundamentals including TCP/IP, UDP, client-server architectures, network protocols, and packet processing.
• Experience designing, debugging, or troubleshooting complex software systems.
• Solid problem-solving and analytical skills.

We operate at the forefront of operating systems, networking, security, and performance engineering, building the transport technologies that underpin Microsoft’s cloud and platform ecosystem. Our work powers critical services and workloads across Windows, Azure, and next-generation cloud infrastructure, enabling secure, reliable, and high-performance communication at global scale.

In Core OS, we are responsible for the Operating Systems that power Azure, Microsoft’s Linux OS, the platforms for Windows Client and Xbox, and our Windows Server ecosystem - through all of these, we support every one of our cloud businesses and billions of customers around the world. In this era of ubiquitous computing, systems software excellence has never been more important for Microsoft. High quality, high-efficiency operating systems and platform components underpin everything we do as a company, from making our systems more reliable for our customers, to increasing our competitiveness by reducing COGS, to delivering new features and capabilities to delight customers - that’s all us!

The Datapath & Transports team builds the networking technologies that carries traffic across Windows, Azure, Xbox, and Microsoft’s cloud services. When you improve a congestion control algorithm or shave microseconds off the datapath here, it ships to billions of devices and some of the largest services on the planet.