Senior HPC Network Engineer — RDMA, Leaf-Spine, Equity

Fuse Energy, LLC; Greater London; Hybrid; GBP 85,000 - 120,000; Full time

Benefits offered by this job

Fully expensed tech to match your need

Private health insurance

Breakfast and dinner allowance

Job summary

Fuse Energy, a London-based energy startup, is hiring a Senior Network Engineer to design, deploy and operate the company's multi-tenant AI cluster network fabric. You will own architecture through day-2 operations, including RDMA fabrics, leaf-spine design, and per-tenant isolation.

You’ll automate provisioning with Python and Ansible, build observability dashboards, and mentor colleagues while expanding the data-centre and office networks.

Qualifications

• 5+ years as a network engineer operating production data centre networks.
• Strong dynamic routing experience (BGP in particular) and overlay/encapsulation design (EVPN/VXLAN).
• Hands-on experience with leaf-spine / Clos fabric design and operation.
• Experience with modern data centre network operating systems and Linux networking stack.
• Practical RDMA fabric experience: lossless Ethernet (RoCEv2) or InfiniBand for GPU workloads.
• Network automation as a working practice: Python, Ansible, source-of-truth config.
• Solid Linux administration fundamentals for host and switch debugging.
• Experience with network telemetry and monitoring (Prometheus/Grafana).
• Experience running corporate/campus networks: wired/wireless, NAC/802.1X, VPN.

Responsibilities

• Design and operate lossless, RDMA-capable fabrics for GPU compute and storage traffic, including QoS and buffer tuning.
• Build and manage leaf-spine data centre fabrics with routed underlay and overlay (BGP, EVPN/VXLAN).
• Implement and maintain per-tenant network isolation across compute, storage and management planes.
• Automate network provisioning, configuration and validation, treating switch config as code (Ansible, Python, NetBox as source of truth).
• Build telemetry and observability for the fabric: dashboards and alerting for congestion and link degradation.
• Troubleshoot performance end to end from optics to NIC/DPU and host communication.
• Operate the out-of-band management network and remote recovery paths.
• Support tenant onboarding: segmentation, addressing, bandwidth and isolation guarantees.
• Write design documentation capturing decisions and trade-offs.
• Own and maintain the office network: wired/wireless, firewalling, VPN and office-to-data-centre connectivity.
• Upskill colleagues through documentation and run-throughs.

Skills

Network engineering

BGP routing

EVPN/VXLAN

RDMA networking

Linux networking

Automation (Python)

Ansible

Tools

NetBox

Prometheus/Grafana

CI/CD pipelines

Packet capture tools

Job description

Fuse Energy, a London-based energy startup, is hiring a Senior Network Engineer to design, deploy and operate the company's multi-tenant AI cluster network fabric. You will own architecture through day-2 operations, including RDMA fabrics, leaf-spine design, and per-tenant isolation.

You’ll automate provisioning with Python and Ansible, build observability dashboards, and mentor colleagues while expanding the data-centre and office networks.