Join a high-performance team building an AI-native cloud platform from the ground up. You will own the virtualization layer, extending a Firecracker fork to achieve sub-25ms cold starts for agentic workloads. This is a foundational role for a systems expert to architect secure, multi-tenant isolation and low-latency compute at massive scale.
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San Francisco, USA$250K – $300K + Equity
Featured roleSan Francisco, USA$250K – $300K + Equity
Virtualization / Compute Systems Engineer at Blaxel — VC-backed AI infrastructure startup
Blaxel is building the 'AWS for AI agents,' and they need a systems expert to own their virtualization layer. Backed by a $7.3M seed round from First Round Capital, this YC X25 startup is extending Firecracker to achieve sub-25ms cold starts for billions of requests. If you thrive on low-level Rust/C++ development, KVM, and kernel-level optimizations, this is your chance to join a founding-scale team of 10 in San Francisco and define the infrastructure that powers the next generation of agentic AI.
Overview
Why this role stands out
Company
Software
Blaxel - First Round Capital backed startup building the AWS for AI agents.
Responsibilities
What you will do
- Design and implement low-level virtualization features on a Firecracker fork, focusing on VM lifecycle and memory optimization.
- Develop kernel-level optimizations and custom device models to minimize latency and maximize throughput for specialized AI workloads.
- Profile and optimize critical paths in the VM creation pipeline while building robust monitoring and observability tools for production.
Candidate profile
Who this is a fit for
- Deep proficiency in Rust and/or C/C++ with a strong understanding of Linux internals like KVM, virtio, and kernel memory management.
- Proven experience with virtualization technologies such as Firecracker, QEMU, or Cloud Hypervisor in a production or open-source context.
- Skilled in systems performance analysis using modern Linux features like eBPF or io_uring to debug across kernel and userspace boundaries.
What makes it remarkable
Why this role is remarkable
- Work directly with technical founders who previously built and sold a multicloud data platform to Europe's largest cloud provider.
- Join a YC X25 company that recently raised $7.3M from First Round Capital and already processes billions of AI agent requests.
- Impact a critical open-source ecosystem by contributing upstream to Firecracker while shipping code that immediately powers top AI startups.
Jack & Jill
How Jack & Jill work together
I get to know what you’re great at, then find roles you’d never find yourself.Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support.
I recruit from Jack’s network and make the intro when I spot a great match.And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate.
About Jack & Jill
Meet Jack
Jack gets to know what you are great at, what you want next, and makes sure Jill considers you for the right opportunities.
How does this work?
Jack's an AI agent for job searching and career coaching. He works for you.
Jill is the AI recruiter working for the company. She recruits from Jack's network.
If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives.
Jack