Location: San Francisco or Croatia

Type: Full-time

Reports to: Engineering Lead, Windows Sandboxes

About Daytona

Daytona is the infrastructure layer for AI agents. We provide secure, isolated, instantly available sandboxes where agents run code, use computers, and train. Our platform powers agent workloads, reinforcement learning, and developer environments for some of the largest AI companies in the world. We closed our Series A earlier this year and have already grown 10x since. We are a small, senior team moving extremely fast.

The role

You will make Windows behave like a serverless primitive: boot fast, snapshot instantly, fork on demand, and hand control to an AI agent over an API. This is unglamorous, high-leverage systems work at the intersection of Linux virtualization and Windows internals, and very few people in the world can do it well.

What You'll Do

• Build the Windows guest stack on KVM/QEMU: virtio drivers, guest agents, image pipelines, unattended provisioning
• Attack Windows boot and login latency; build snapshot/restore and fork that actually work for Windows guests
• Build the control plane surfaces agents use: input injection, display streaming, file transfer, process and app lifecycle APIs
• Automate image builds and updates: patching, software installation, sysprep, golden image management at fleet scale
• Instrument and improve density, cost, and reliability of Windows hosts
• Debug across the boundary: hypervisor on one side, Windows kernel and services on the other

What We're Looking For

• 5+ years of systems engineering in production
• Real experience with Windows guests on Linux hypervisors (KVM/QEMU + virtio) or equivalent depth in Windows virtualization internals
• Strong Windows internals: boot, services, session management, registry, PowerShell/WinRM automation