Senior Network Engineer (AI/GPU Clusters)

Location: EMEA, including London, Norway, and the UK; regular travel to deployment sites across Europe is required.

Company

Nscale provides GPU cloud infrastructure for AI start-ups and enterprise customers, focusing on high-performance, cost-effective, and environmentally responsible AI computing.

What you will do

• Deploy, configure, and validate high-performance Ethernet and InfiniBand fabrics for large GPU clusters.
• Bring up front-end, storage, management, and WAN edge networks for new sites and expansions.
• Run network acceptance testing and performance validation before customer handover.
• Troubleshoot routing, switching, optics, and cabling issues during network build and early operation.
• Improve reference designs, bills of materials, build standards, and automation for provisioning and validation.
• Coordinate with Network Architecture, Technical Program Managers, Data Centre Operations, and vendors, while maintaining runbooks and documentation.

Requirements

• 5+ years of network engineering experience in large-scale data centre, cloud, or HPC environments.
• Experience with a hyperscaler, major network vendor, or comparable large-scale network.
• Strong knowledge of BGP, OSPF, EVPN/VXLAN, ECMP, and Layer 2/Layer 3 data centre design.
• Experience deploying and operating cluster networks, ideally including InfiniBand or RoCE fabrics.
• Practical network automation experience with Python, Ansible, or similar tools.
• Willingness to travel across Europe to deployment sites as needed.

Nice to have

• Experience building networks for GPU clusters or AI training environments.
• Familiarity with HPC topologies such as Fat Tree and Rail, plus 400G/800G optics.
• Experience with SONiC, Cumulus, WAN, peering, or DWDM.
• CCNP/CCIE, JNCIP/JNCIE, or NVIDIA networking certifications.

Culture & Benefits

• Ownership, accountability, openness, and transparency are central to the working environment.
• Hands-on work building infrastructure that powers AI clusters and determines their performance.
• Inclusive and equitable workplace with accommodations available for individual needs.