Senior GPU Cluster Network Engineer

About the role

Sciforium is building next‑generation AI infrastructure and needs a senior engineer to own the networking stack of its large‑scale GPU clusters. You will design, bring up, and operate the full fabric—from InfiniBand/RoCE compute fabrics to perimeter firewalls and cloud interconnects.

Key responsibilities

• Architect greenfield network designs for new GPU clusters, including compute, storage, in‑band, out‑of‑band, and perimeter topologies.
• Select and justify RDMA fabrics (InfiniBand or lossless Ethernet/RoCE v2) for training and inference workloads.
• Specify switches, NICs, optics, and cabling; produce port maps and cable schedules for hardware operations.
• Define IP addressing, VLAN/VRF segmentation, and BGP/EVPN‑VXLAN underlay‑overlay architecture.
• Configure and validate RoCE v2 at scale (PFC, ECN/DCQCN, QoS) and manage InfiniBand subnet managers, adaptive routing, and SHARP.
• Run performance benchmarks (perftest, nccl‑tests) and troubleshoot fabric‑level issues.
• Maintain routing protocols (BGP, OSPF, ECMP) and switch operating systems across multiple vendors.
• Implement network‑as‑code pipelines using NetBox, Ansible/Nornir/NAPALM, and Git‑based CI.
• Design dark‑fiber/DWDM inter‑site links and hybrid‑cloud connectivity (AWS Direct Connect, Azure ExpressRoute, GCP Interconnect).

Required profile

• 7+ years designing and operating production data‑center networks, with experience on at least one large‑scale HPC/AI cluster fabric.
• Deep expertise in routing (BGP, EVPN‑VXLAN, OSPF) and RDMA (RoCE v2 tuning or InfiniBand management).
• Hands‑on experience with 100‑800 Gbps optics, high‑radix switches, and Clos/rail‑optimized topologies.
• Proficiency in network automation (Python, Ansible, Git‑based workflows).
• Knowledge of host‑side RDMA stacks (MOFED, DOCA, GPUDirect) and how NCCL/RCCL map onto the fabric.

Required skills

• InfiniBand, RoCE v2, BGP, EVPN‑VXLAN, OSPF, ECMP, VRF
• Arista EOS, NVIDIA Cumulus, Cisco NX‑OS, Junos, SONiC
• Python, Ansible, Nornir, NAPALM, Git, CI pipelines
• NetBox, Prometheus, Grafana, sFlow, gNMI
• AWS Direct Connect, Azure ExpressRoute, GCP Interconnect

What we offer

• Medical, dental, and vision insurance
• 401k plan
• Daily lunch, snacks, and beverages
• Flexible time off
• Competitive salary and equity