Staff Cloud Hypervisor R&D

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 t