Senior Software Engineer, Windows Sandboxes

Recruiting From Scratch • San Francisco, CA

23h • Onsite

About The Position

We're representing a rapidly growing infrastructure company building the compute layer for AI agents. Its platform provides secure, isolated, instantly available sandboxes where AI agents can execute code, interact with computers, and run training workloads. Following its Series A, the company has already grown 10x and is now expanding its infrastructure to make Windows environments available as an on-demand, serverless primitive. The team is solving difficult systems problems spanning Linux virtualization and Windows internals—making Windows VMs boot quickly, snapshot and restore efficiently, fork on demand, and expose desktop applications directly to AI agents through APIs. This is a deeply technical systems engineering role for someone comfortable debugging across hypervisors, operating systems, drivers, and production infrastructure.

Requirements

• 5+ years of professional systems, infrastructure, virtualization, or platform engineering experience.
• Hands-on production experience running Windows guests on Linux hypervisors such as KVM/QEMU.
• Alternatively, deep Windows virtualization experience with strong knowledge transferable to KVM/QEMU and virtio environments.
• Strong understanding of Windows internals, including boot processes, services, session management, and the registry.
• Experience automating Windows environments using PowerShell, WinRM, unattended provisioning, or similar tooling.
• Strong systems programming skills with Go, Rust, C, C++, or C# for systems-level development.
• Experience debugging issues across virtualization and operating system boundaries.
• Strong understanding of production infrastructure, reliability, observability, and performance optimization.
• Comfortable working close to operating systems, drivers, networking, and virtualization layers.
• High ownership mindset with experience operating and supporting the production systems you build.
• Comfortable solving ambiguous, low-level engineering problems within a small and fast-moving team.

Nice To Haves

• Experience with remote display protocols or streaming infrastructure such as RDP, SPICE, or WebRTC.
• Windows driver development experience.
• Experience developing guest agents or other software that interfaces directly with virtualization platforms.
• Background building VDI, Cloud PC, desktop virtualization, or remote workstation infrastructure.
• Experience with desktop automation or large-scale UI testing infrastructure.
• Experience building infrastructure for computer-use AI agents.
• Familiarity with Packer or other image-as-code tooling for Windows environments.
• Experience optimizing Windows VM startup, snapshotting, image management, or host density.
• Background at a virtualization, cloud infrastructure, serverless compute, VDI, or hyperscaler infrastructure organization.
• Experience building control planes or APIs for programmatic interaction with virtual machines.

Responsibilities

• Build and productionize the Windows guest stack running on KVM/QEMU infrastructure.
• Develop and integrate virtio drivers, guest agents, image pipelines, and unattended provisioning systems.
• Optimize Windows boot, session initialization, and login latency to create an instant-start sandbox experience.
• Build snapshot, restore, pause, and fork capabilities for Windows virtual machines.
• Develop control-plane APIs that allow AI agents to interact programmatically with Windows environments.
• Build infrastructure for input injection, display streaming, file transfer, and application and process lifecycle management.
• Automate Windows image creation, software installation, patching, Sysprep, and golden image management.
• Build scalable image update and deployment infrastructure across a production fleet.
• Instrument Windows hosts and improve VM density, infrastructure utilization, reliability, and cost per sandbox.
• Debug difficult systems problems spanning the KVM/QEMU hypervisor, Windows kernel, services, drivers, and guest environments.
• Build observability and automation that make Windows infrastructure reliable at production scale.
• Own systems from architecture and implementation through deployment, operations, incident response, and ongoing improvement.

Benefits

• Competitive base salary plus equity.
• Full-time position
• Opportunity to work on unusual systems challenges at the intersection of Linux virtualization, Windows internals, and AI agent infrastructure.
• Join shortly after the company's Series A during a period of rapid growth, with the platform already having grown approximately 10x.
• Work within a small, senior engineering team where individual contributors have substantial technical and production ownership.
• Opportunity to help create a serverless Windows platform where AI agents can instantly launch, control, snapshot, and fork real desktop environments.

What This Job Offers

• Job Type: Full-time
• Career Level: Senior
• Education Level: No Education Listed