Staff Systems Software Engineer, Linux Kernel at Crusoe

Crusoe's mission is to accelerate the abundance of energy and intelligence. We’re crafting the engine that powers a world where people can create ambitiously with AI — without sacrificing scale, speed, or sustainability. Be a part of the AI revolution with sustainable technology at Crusoe. Here, you'll drive meaningful innovation, make a tangible impact, and join a team that’s setting the pace for responsible, transformative cloud infrastructure. Staff Systems Software Engineer, Linux Kernel San Francisco, Sunnyvale (On-site) ABOUT THE ROLE Crusoe is seeking a Staff Linux Kernel Engineer to serve as the primary technical authority for our operating system and hardware-interface layer. This is a "heavy-lifting" engineering role designed for someone who views the Linux kernel not just as an OS, but as a programmable substrate for AI performance. As a Staff Engineer, you will own the most critical paths of our compute stack. You will be responsible for upstream-quality development, custom kernel modules, and the low-level orchestration of memory and I/O that allows our GPU clusters to operate at the theoretical limits of the silicon. You will bridge the gap between baremetal hardware and the virtualization layer, ensuring that Crusoe's "Metal-as-a-Service" offering is the most performant in the industry. WHAT YOU’LL BE WORKING ON CORE KERNEL ARCHITECTURE & DEVELOPMENT - Architect and implement enhancements to the Linux kernel’s memory management (MM), process scheduler, and I/O stack specifically for high-tenancy AI/HPC workloads. - Develop and maintain out-of-tree kernel modules and drivers that manage high-speed interconnects (NVSwitch/NVLink) and hardware accelerators. - Identify, backport, and contribute fixes and features to the mainline Linux kernel, ensuring Crusoe remains at the forefront of kernel innovation. HARDWARE-SOFTWARE CO-DESIGN - PCIe & IOMMU Interfacing: Lead the implementation of VFIO and SR-IOV strategies to provide secure, near-zero-latency hardware passthrough to virtualized environments. - DMA & GPUDirect RDMA: Optimize DMA mapping and memory pinning strategies to facilitate high-speed data transfers between NICs and GPUs without CPU intervention. - Hardware Abstraction: Work with hardware vendors to debug and influence the design of firmware and silicon-level features that impact kernel stability and performance. PERFORMANCE OBSERVABILITY & ROOT-CAUSE ANALYSIS - Advanced Profiling: Utilize eBPF, ftrace, and perf to build deep observability into kernel-space bottlenecks and latency spikes. - Deep-System Debugging: Lead the investigation into complex system-level failures, including kernel panics, memory leaks, and non-deterministic hardware behavior. - Benchmarking: Establish gold-standard performance metrics for kernel-level operations that directly impact AI training times and inference throughput. WHAT YOU’LL BRING TO THE TEAM - 8+ years of deep Systems Programming experience, with at least 5 years focused specifically on Linux Kernel development. - Profound understanding of kernel internals, including the VFS, block layer, task scheduling, and interrupt handling. - C & Assembly Proficiency: Expert-level mastery of C and the ability to read/debug architecture-specific assembly (x86_64, ARM64). - Virtualization-at-the-Metal: Extensive experience with KVM internals and the interaction between the hypervisor and the host kernel. - Deep knowledge of SLAB/SLUB allocators, page table management, and NUMA-aware memory allocation strategies. - Expertise in eBPF for both observability and networking/security (XDP) applications. - Experience leading large-scale architectural shifts and mentoring senior engineers on the nuances of systems-level safety and performance. BENEFITS - Industry competitive pay - Restricted Stock Units in a fast-growing, well-funded technology company - Health insurance package options (HDHP and PPO, vision, and dental) - Employer contributions to HSA accounts - Paid Parental Leave & Life Insurance - 401(k) with a 100% match up to 4% of salary - Generous paid time off and holiday schedule - $300/month commuter benefit and tuition reimbursement - Subscription to the Calm app and MetLife Legal COMPENSATION RANGE $208,600 - $254,40000 + Bonus. Restricted Stock Units are included in all offers. Compensation is determined by the applicant's knowledge, education, 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.