Hiring: GPU Cluster Engineer, Networking Company: Sciforium Location: San Francisco, CA Job Posted Time: 2026-09-16 23:47:43 Employment Type: Remote Target Skills & Keywords : AWS, Ansible, Azure, BGP, Fiber, Firmware, GCP, Git, Grafana, Kubernetes, Prometheus, Python, VPC, VPN About the job Experience: •7+ years designing and operating production data center networks, including at least one large-scale HPC/AI cluster fabric (InfiniBand or RoCE v2) you designed or ran. Required Skills: •Fabric Architecture & Cluster Network Design •Greenfield Design: Architect the full network for new GPU clusters — compute/backend fabric, storage network, in-band frontend, out-of-band management (BMC/IPMI), and perimeter — including topology (fat-tree/Clos, rail-optimized), oversubscription analysis, and growth planning. •RDMA Fabric Selection: Design and justify InfiniBand (NDR/XDR, Quantum-class) vs. lossless Ethernet/RoCE v2 (Spectrum-X, Tomahawk-class) fabrics for training and inference workloads, including scale-up domains (NVLink/NVSwitch, NVL72-class rack systems). •Hardware & Physical Plant: Specify switches, NICs (ConnectX/BlueField), optics (400/800G OSFP/QSFP-DD), and cabling plans; produce the port maps and cable schedules Hardware Operations executes. •Logical Design: Own IP addressing plans, VLAN/VRF segmentation, and BGP/EVPN-VXLAN underlay-overlay architecture. •Lossless Ethernet: Configure and validate RoCE v2 at scale — PFC, ECN/DCQCN congestion control, QoS/DSCP classification, buffer tuning — and prove no-drop behavior under full training load. •InfiniBand Operations: Run subnet managers (UFM/OpenSM), adaptive routing, SHARP in-network aggregation, partition keys, and virtual-lane QoS. •Fabric Validation: Benchmark and sign off new fabrics with perftest/ib_write_bw and nccl-tests/rccl-tests; verify GPUDirect RDMA paths and topology-aware placement with the Systems & Platform team. Qualifications: •7+ years designing and operating production data center networks, including at least one large-scale HPC/AI cluster fabric (InfiniBand or RoCE v2) you designed or ran. •Expert-level routing and switching: BGP (including EVPN-VXLAN), OSPF, ECMP, VRF segmentation, across at least two major vendor platforms. •Deep RDMA expertise: lossless RoCE v2 tuning (PFC/ECN/DCQCN) and/or InfiniBand fabric management (subnet managers, adaptive routing, SHARP). •Applied hands-on capability in 100–800G optics, high-radix switching, and Clos/rail-optimized topologies. •Production network security experience: enterprise firewalls, site-to-site and remote-access VPNs, segmentation design. •Network automation proficiency: Python plus Ansible (or Nornir/NAPALM), with Git-based configuration workflows. •Solid functional working knowledge of the host-side RDMA stack (MOFED/DOCA, NIC tuning, GPUDirect) and how NCCL/RCCL collectives map onto physical fabric. •Cloud networking experience: VPC design and dedicated interconnects (Direct Connect/ExpressRoute class). •Dark fiber / DWDM procurement and operations experience. •BlueField DPU or SmartNIC deployments. Interested candidates, please apply directly through the job posting on company's career page or try via AI auto apply on this platform. Don't miss this opportunity to join a forward-thinking team!