AI Insights
Crusoe

Staff Cloud Hypervisor R&D

Crusoe · San Francisco, California, US
full-timestaff (7-15 yrs)Posted 47d ago
Software EngineeringIC4IC + ManagementOn-site
StackKVMQEMUCC++RustLinux kernelSR-IOVVFIOmdevVirtIOvhost-userIntel VT-xAMD-VEPT/NPTHugePageseBPFperfftraceNVIDIA GPU virtualizationInfiniBandRoCEBlueField DPUPCIeSmartNIC

Summary

Crusoe is seeking a Staff Cloud Hypervisor R&D Engineer to lead the architecture of their next-generation virtualization stack, optimizing GPU/DPU pass-through, eliminating the "virtualization tax," and solving hard AI infrastructure challenges like live migration of large VRAM workloads at their onsite SF/Sunnyvale locations.

About the role

Crusoe is on a mission to accelerate the abundance of energy and intelligence. As the only vertically integrated AI infrastructure company built from the ground up, we own and operate each layer of the stack — from electrons to tokens — to power the world's most ambitious AI workloads. When you join Crusoe, you join a team that is building the future, faster.

We're in the midst of the greatest industrial revolution of our time. The demand for AI compute is boundless, and power is a bottleneck. We're solving that — with an energy-first approach that makes AI infrastructure better for the world and faster for the people innovating with AI.

We're looking for problem-solving, opportunity-finding teammates with a sense of urgency, who believe in the scale of our ambition and thrive on a path not fully paved — people who want to grow their careers alongside a team of experts across energy, manufacturing, data center construction, and cloud services.

If you want to do the most meaningful work of your career, help our customers and partners advance their AI strategies, and be part of a high-performing team that believes in each other, come build with us at Crusoe.

Senior/Staff Cloud Hypervisor R&D

Location: San Francisco, CA; Sunnyvale, CA (Onsite)

Role Mission

At Crusoe, we are building the "engine room" of the AI revolution. We are seeking a Staff Cloud Hypervisor R&D Engineer to serve as the lead architect for our next-generation virtualization stack. In this role, you will move beyond standard virtualization to design a "Greenfield" hypervisor environment where GPUs, DPUs, and high-speed interconnects are first-class citizens. You will be responsible for eliminating the "virtualization tax," ensuring our cloud infrastructure delivers bare-metal performance for the world’s most demanding AI/ML workloads.

What You’ll Be Working On:

  • Next-Gen Hypervisor Architecture: Lead the R&D and implementation of core hypervisor components (KVM, QEMU, or custom Rust-based solutions) specifically optimized for massive-scale GPU fleets.

  • AI Hardware Virtualization: Develop and refine advanced hardware pass-through and abstraction techniques (SR-IOV, VFIO, mdev) to ensure NVIDIA GPUs and BlueField DPUs operate with near-zero latency in a multi-tenant environment.

  • The "Holy Grail" Challenges: Solve high-stakes technical hurdles such as live migration for AI workloads with 80GB+ VRAM and optimizing PCIe peer-to-peer communication between virtualized accelerators.

  • Performance Research & Profiling: Conduct deep-dive bottleneck analysis across the entire stack—from CPU microarchitecture and MMU virtualization to guest OS scheduling—to minimize jitter and maximize throughput.

  • Open Source Leadership: Actively contribute to and maintain upstream open-source virtualization projects, positioning Crusoe as a thought leader in the Linux kernel and virtualization communities.

  • Security & Isolation: Architect robust security boundaries for AI-native cloud infrastructure, balancing high-performance hardware access with strict multi-tenant isolation and hardening.

What You’ll Bring to the Team:

  • 7+ Years of Experience: Proven track record in hypervisor internals, kernel development, or low-level systems programming.

  • Deep Virtualization Expertise: Expert-level knowledge of CPU virtualization (Intel VT-x, AMD-V) and memory virtualization (EPT/NPT, HugePages). You should be comfortable discussing the nuances of VMExit overhead.

  • Hardware-Software Integration: Experience working with specialized AI hardware, including GPUs, InfiniBand/RoCE NICs, and SmartNICs/DPUs.

  • Programming & Tooling: Mastery of C and C++ is required; proficiency in Rust for modern systems programming is highly preferred. Experience with QEMU, KVM, and Linux kernel debugging tools (perf, ftrace, eBPF).

  • I/O Mastery: Deep understanding of VirtIO, vhost-user, and hardware-accelerated I/O paths.

  • Technical Leadership: Experience leading complex, cross-functional projects that bridge the gap between hardware engineering and cloud control planes.

Benefits:

  • Industry competitive pay

  • Restricted Stock Units in a fast growing, well-funded technology company

  • Health insurance package options that include HDHP and PPO, vision, and dental for you and your dependents

  • Employer contributions to HSA accounts

  • Paid Parental Leave

  • Paid life insurance, short-term and long-term disability

  • Teladoc

  • 401(k) with a 100% match up to 4% of salary

  • Generous paid time off and holiday schedule

  • Cell phone reimbursement

  • Tuition reimbursement

  • Subscription to the Calm app

  • MetLife Legal

  • Company paid Commuter FSA benefit of $300 per month

Compensation:

Compensation will be paid in the range of $204,000 - $247,000. Restricted Stock Units are included in all offers. Compensation to be determined by the applicant’s education, experience, knowledge, skills, and abilities, as well as internal equity and alignment with market data.

Crusoe is an Equal Opportunity Employer. Employment decisions are made without regard to race, color, religion, disability, genetic information, pregnancy, citizenship, marital status, sex/gender, sexual preference/ orientation, gender identity, age, veteran status, national origin, or any other status protected by law or regulation.

What you'll do

1Lead R&D and implementation of core hypervisor components (KVM, QEMU, or custom Rust-based solutions) optimized for large-scale GPU fleets
2Develop and refine advanced hardware pass-through and abstraction techniques (SR-IOV, VFIO, mdev) for NVIDIA GPUs and BlueField DPUs in multi-tenant environments
3Solve high-stakes challenges such as live migration for AI workloads with 80GB+ VRAM and PCIe peer-to-peer communication between virtualized accelerators
4Conduct deep-dive performance profiling and bottleneck analysis across the full stack (CPU microarchitecture, MMU virtualization, guest OS scheduling)
5Actively contribute to and maintain upstream open-source virtualization projects, representing Crusoe in Linux kernel and virtualization communities
6Architect robust security boundaries balancing high-performance hardware access with strict multi-tenant isolation and hardening

Requirements

7+ years of experience in hypervisor internals, kernel development, or low-level systems programming
Expert-level knowledge of CPU and memory virtualization (Intel VT-x, AMD-V, EPT/NPT, HugePages) including VMExit overhead
Hands-on experience with GPU/DPU hardware pass-through techniques (SR-IOV, VFIO, mdev) and AI-class hardware like NVIDIA GPUs and InfiniBand/RoCE NICs
Mastery of C and C++ with strong proficiency in Rust for systems programming and familiarity with QEMU, KVM, and Linux kernel debugging tools
Deep understanding of I/O virtualization paths including VirtIO, vhost-user, and hardware-accelerated I/O

Nice to have

Rust
Open source upstream contributions (Linux kernel or virtualization projects)
Experience leading cross-functional projects bridging hardware engineering and cloud control planes

Role overview

Role family
Software Engineering
Level
IC4 — platform
Experience
7–15 years
Type
Hybrid (IC + Management)
Remote policy
On-site
Visa sponsorship
Not offered

Tech stack analysis

LANGUAGES
CC++Rust
FRAMEWORKS
QEMUKVMVirtIOvhost-user
INFRASTRUCTURE
Linux kernelSR-IOVVFIOmdevPCIeInfiniBandRoCEBlueField DPUNVIDIA GPU
TOOLS
perfftraceeBPF

Green flags

5 items
Salary range is fully disclosed ($204K–$247K) with RSUs included in all offers — strong transparency signalcompensation

Discover all 5 green flags for this role

Sign up free →

Benefits breakdown

HEALTH & WELLNESS
HDHP health insurance option
PPO health insurance option
Vision insurance
Dental insurance (for employee and dependents)
Teladoc telehealth access
Employer HSA contributions
Paid life insurance
Short-term disability insurance
Long-term disability insurance

See all benefits organized by category — health, financial, time off & more

Sign up free →

Hiring insights

JD quality
9/10
Urgency
high
Autonomy
high
Team size
small (2-5)

See JD quality score, hiring urgency & team details

Sign up free →

Red flags

PRO3 items
Onsite-only requirement in SF/Sunnyvale with no remote or hybrid option may limit candidate pool and flexibilitywork life balance

See all 3 red flags — what the JD isn't telling you

Sign up free →

Interview insights

PRO
Rounds
5
Duration
4 wks
Difficulty
very hard
Take-home
Yes

Get full interview breakdown — rounds, likely topics & prep tips

Sign up free →

Career path

PRO
Next roles
Principal Cloud Infrastructure EngineerDistinguished Engineer – VirtualizationEngineering Director – Cloud Platform

See where this role leads — full career progression

Sign up free →
About the company

Crusoe is a clean compute infrastructure company that repurposes stranded and wasted energy to power AI and high-performance computing workloads. Its climate-aligned cloud platform delivers GPU compute for AI training and inference while reducing carbon emissions. Crusoe is backed by over $600 million in funding.

HQDenver, CO, USA
Interview difficultyvery hard
Build vs Maintainbuild
Cross-functionalYes