Principal Systems Software Engineer 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. PRINCIPAL SYSTEMS SOFTWARE ENGINEER San Francisco, Sunnyvale (On-site) ABOUT THE ROLE Crusoe is seeking a Principal Systems Architect to serve as the visionary lead for our next-generation AI infrastructure. This is a role for an industry-recognized expert who has already "seen the movie" at hyperscale and is ready to redefine the I/O path for the age of generative AI. In this position, you aren't just building a cloud; you are designing the fluid fabric that unifies Bare-Metal-as-a-Service (BMaaS), Intelligent IaaS, and Elastic CaaS into a single, high-performance pool of intelligence. You will bridge the gap between silicon and software, advising executive leadership on critical hardware/software co-design pivots while remaining hands-on enough to lead R&D teams in shipping production-grade kernel and orchestration code. WHAT YOU’LL BE WORKING ON UNIFYING PILLARS: - Bare-Metal-as-a-Service (BMaaS): Architecting the systems that deliver raw GPU throughput via zero-latency InfiniBand/RDMA fabrics, ensuring that massive-scale training workloads perform at the theoretical limits of the hardware. - Intelligent IaaS: Designing a highly optimized, thin virtualization layer using KVM or custom micro-VMs. Your goal is to provide enterprise-grade isolation and multi-tenancy without the virtualization tax on performance. - Elastic CaaS: Building a high-performance container substrate (utilizing Kubernetes or Slurm) that allows AI workloads to burst and scale across heterogeneous GPU nodes instantly. MASTERING THE I/O PATH - Leading the architectural design of our internal cloud fabric, drawing on experience building at hyperscalers (OCI, AWS, GCP) or top-tier neoclouds. - Driving the technical roadmap for SR-IOV, RDMA, and virtualized GPU scheduling. You will hold the expertise (and potentially the patents) that define how we handle high-density GPU interconnects. - Leading elite R&D workstreams to prototype and productionize new ways of managing memory, networking, and compute that don't yet exist in standard cloud distributions. A DAY IN THE LIFE - Drafting white papers and RFCs that define the next two years of Crusoe’s compute and networking stack. - Working alongside Staff and Senior engineers to debug complex race conditions in the I/O path or optimize kernel-level memory pinning for GPU clusters. - Representing Crusoe in open-source communities or industry forums to influence the direction of cloud-native AI infrastructure. YOU WILL THRIVE IN THIS ROLE IF YOU HAVE: - 12+ years of experience designing and shipping core infrastructure at a major hyperscaler (OCI, AWS, Azure, GCP) or a specialized HPC cloud. - Deep, authoritative knowledge of the Linux kernel, virtualization internals (KVM/QEMU/Firecracker), and high-performance networking (RoCE v2, InfiniBand). - Proven ability to design software that maximizes the performance of NVIDIA/AMD GPUs and high-speed NICs. - Experience leading cross-functional R&D teams through high-ambiguity projects and delivering production-ready systems. - A portfolio of significant contributions to the field, which may include patents, major open-source contributions, or published research in distributed systems. - The rare ability to explain the nuances of memory-mapped I/O to an engineer and the business value of a new fabric architecture to a Board member. BENEFITS - Industry-leading competitive pay and significant equity - 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 PTO and holiday schedule - $300/month commuter benefit and tuition reimbursement - Subscribed access to Calm and MetLife Legal COMPENSATION RANGE $260,000 - $340,000 + Significant Equity & Bonus. Compensation is determined by the applicant's depth of expertise, previous impact at scale, and alignment with our architectural goals. 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.