HPC Network Engineer

Fuse Energy Supply; Greater London; On-site; GBP 63,000 - 103,000; Full time

Benefits offered by this job

Equity sign-on bonus

Biannual bonus

Fully expensed tech

Breakfast and dinner allowance

Job summary

Fuse Energy seeks an experienced network engineer to design, deploy, and operate lossless, RDMA-capable fabrics for GPU compute and storage traffic. You will build and manage leaf-spine data centre fabrics with both underlay and overlay designs, and ensure tenant isolation across compute, storage, and management planes.

You will automate provisioning, collect telemetry, and maintain observability with dashboards and alerts.

Qualifications

• 5+ years as a network engineer operating production data centre networks.
• Strong dynamic routing experience, particularly BGP, plus overlay/encapsulation design and troubleshooting such as EVPN/VXLAN.
• Leaf-spine/Clos fabric design and operation.
• Comfort with the Linux networking stack, not just vendor CLI.
• Practical RDMA fabric experience (RoCEv2, PFC/ECN/DCQCN or InfiniBand).
• Network automation using Python, Ansible, and config-as-code.
• Solid Linux administration fundamentals.
• Experience with telemetry/monitoring (Prometheus/Grafana, sFlow/IPFIX).
• Experience with corporate/campus networks (NAC/802.1X, VPN).
• Clear communicator, able to teach and document for others.

Responsibilities

• Design and operate lossless, RDMA-capable fabrics for GPU compute and storage traffic.
• Build and manage leaf-spine data centre fabrics with underlay and overlay design.
• Maintain per-tenant network isolation across compute/storage/management planes.
• Automate network provisioning and validation, treat config as code.
• Develop telemetry/observability with dashboards and alerts for congestion.
• Troubleshoot end-to-end performance from optics to NIC/DPU config.
• Operate the out-of-band management and remote recovery paths.
• Support tenant onboarding including segmentation and capacity planning.
• Write design docs with decisions and rationale.
• Own and maintain the office network and connectivity to data centres.

Skills

5+ years network engineering

BGP

EVPN/VXLAN

Leaf-spine/Clos fabrics

Linux networking

RDMA (RoCEv2, PFC/ECN/DCQCN)

InfiniBand

Network automation (Python)

Ansible

Prometheus/Grafana

sFlow/IPFIX

WAN/LAN with NAC/802.1X/VPN

Communication & teaching

CCNP/CCIE (valued)

Tools

Ansible

Python

Prometheus

Grafana

sFlow

IPFIX

Job description

Salary: £63,000 - 103,000 per year

Requirements:

• 5+ years as a network engineer operating production data centre networks
• Strong dynamic routing experience, particularly BGP, plus overlay/encapsulation design and troubleshooting such as EVPN/VXLAN
• Hands-on experience with leaf-spine / Clos fabric design and operation
• Experience with modern data centre network operating systems and comfort with the Linux networking stack, not just a vendor CLI
• Practical RDMA fabric experience, such as lossless Ethernet with RoCEv2 and PFC/ECN/DCQCN tuning, or InfiniBand, with an understanding of why lossless behaviour matters for GPU workloads
• Network automation as a working practice, including scripting such as Python, configuration management such as Ansible, config generation from a source of truth, and version-controlled changes
• Solid Linux administration fundamentals, with the ability to debug from the host side as well as the switch side
• Experience with network telemetry and monitoring, such as Prometheus/Grafana, sFlow/IPFIX, or streaming telemetry
• Experience running corporate/campus networks, including wired and wireless, switching, NAC/802.1X, VPN, and remote access
• Clear communicator who enjoys teaching and can document, pair, and run sessions that bring less network-savvy colleagues up to speed
• Relevant certifications such as CCNP/CCIE or equivalent are valued as evidence of depth, not a gate

Responsibilities:

• Design and operate lossless, RDMA-capable fabrics for GPU compute and storage traffic, including QoS, congestion control, and buffer tuning at scale
• Build and manage leaf-spine data centre fabrics, with routed underlay and overlay design
• Implement and maintain per-tenant network isolation across compute, storage, and management planes
• Automate network provisioning, configuration, and validation, treating switch config as code and deploying through CI
• Build telemetry and observability for the fabric, including dashboards and alerting that catches congestion and link degradation early
• Troubleshoot performance issues end to end, from optics and cabling through switch buffers to NIC/DPU configuration and collective-communication behaviour on the hosts
• Operate the out-of-band management network, console access, and remote recovery paths
• Support tenant onboarding, including segmentation and addressing, bandwidth and isolation guarantees, and capacity planning as the cluster scales
• Write clear design documentation capturing decisions, rationale, and rejected alternatives
• Own and maintain the office network, including wired and wireless infrastructure, firewalling, VPN/remote access, and connectivity between the office and data centre environments
• Upskill colleagues on networking through documentation, run-throughs, and pairing so the wider team can operate and troubleshoot the fabric confidently

Technologies:

• AI
• Ansible
• Ethernet
• Fabric
• Grafana
• InfiniBand
• Support
• LESS
• Linux
• Network
• Prometheus
• Python
• RDMA
• VPN
• Bootstrap
• Cisco
• Datadog
• Firewall
• FortiGate
• Flow
• NodeJS

More:

We are Fuse Energy, a forward-thinking renewable energy startup on a mission to deliver a terawatt of renewable energy fast. We combine first-principles thinking with cutting-edge technology to build a radically better energy system. We have raised $210M from top-tier investors including Multicoin, Balderton, Lakestar, Accel, Creandum, Lowercarbon, Ribbit, Box Group, and strategic angels such as Nico Rosberg, the Co-Founder of Solana, and GPs behind Meta, Revolut, Spotify, Uber, and more. This is a full-time role focused on designing, deploying, and operating the network fabric for our multi-tenant AI cluster, plus owning the office network and acting as the networking authority for the company. We offer a competitive salary, an equity sign-on bonus, a biannual bonus scheme, fully expensed tech to match your needs, and breakfast and dinner allowance for office-based employees.