Principal Software Engineer - C++

Overview

The Windows App for the web is a full Windows client implemented inside a browser runtime. It powers Azure Virtual Desktop and Windows 365 by translating operating system expectations-graphics, input, media, identity, security and device access-into something that can execute reliably inside modern web platforms, bringing a "like-local" Windows experience to millions of enterprise users.

We're seeking a Principal Software Engineer to operate in the foundational layers of our web client, where architectural decisions directly affect performance, reliability, security posture, and long-term evolution. This role serves as a technical anchor for the client, with hands-on work spanning rendering and graphics pipelines, protocol stacks, Web Assembly-based components, media and device redirection, authentication, telemetry, and the isolation boundaries that allow a browser to behave like a high-fidelity Windows endpoint.

At this level, impact comes from working on the hardest parts of the stack while providing technical clarity through design choices and trade-offs, shaping how the system is built, integrated, and evolves as browser capabilities, cloud infrastructure, and Windows workloads continue to converge.

We're a collaborative, high-energy group that values curiosity, craftsmanship, and a growth mindset.

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Why this problem space matters

This work defines how Windows runs when the browser is the platform. The solutions ship at global scale and are constrained by real-world networks, devices, and security models. For engineers who enjoy working close to the limits of what the web runtime allows-and extending it responsibly-this is a rare problem space.

What you'll work on

You'll operate primarily in the foundational layers of the client, where performance, correctness, and constraints are explicit:

• Rendering and interaction pipelines
  • High-performance remote graphics using Canvas, WebGL/WebGPU, and Web Assembly
  • Input fidelity across keyboard, mouse, touch, pen, and specialized devices
  • Latency control, frame pacing, bandwidth adaptation, and GPU utilization
• Client protocol and transport architecture
  • Design and evolution of remoting protocols optimized for web runtimes
  • Reliability, congestion control, and session resilience across heterogeneous networks
  • Tight coordination between browser client, gateways, and cloud services
• Web Assembly and native code integration
  • Performance-critical C/C++ components compiled to WASM
  • Memory models, threading, SIMD, and sandbox constraints
  • Deep integration with Chromium APIs and browser execution models
• Media and device redirection
  • Audio/video pipelines supporting Teams optimization and real-time collaboration
  • Multimedia redirection with strict latency and synchronization requirements
  • Device and peripheral redirection (e.g., smart cards, cameras, microphones) mapped into web-safe abstractions
• Identity, security, and isolation
  • Smart card redirection, Web Authn/FIDO flows, and authentication pass-through
  • Clear trust boundaries between local device, browser, and remote session
  • Secure-by-design client architectures that preserve performance and usability

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

At this level, the role is about technical ownership and direction.

You will:

• Define and drive end-to-end designs spanning browser, protocol, and cloud
• Make architectural calls under real constraints imposed by browsers and security models
• Identify performance ceilings and systematically remove them
• Partner across Windows, Chromium, Teams, and Azure to align deep technical decisions
• Raise the technical bar through design reviews, mentorship, and examples.

Qualifications

Required Qualifications:

• Bachelor's in Computer Science or related field AND 6+ years of technical engineering experience including web technologies and…