Network Engineer (Datacentre, Arista, Cisco)

Location: Hybrid, London, Greater London, England, United Kingdom

Salary: £80,000–£110,000 per annum, plus benefits

Company

Network consultancy specialising in datacentre transformation for financial markets environments.

What you will do

• Design, build, and operate spine-leaf (Clos) datacentre fabrics using Cisco and Arista technologies.
• Deploy VXLAN/EVPN overlays, including multi-tenant VRF segmentation, and manage routed underlays using BGP, OSPF, or IS-IS with ECMP and fast failover.
• Plan capacity, oversubscription, and scale-out of leaves and spines; deliver resilient server connectivity with MLAG/vPC and LACP.
• Perform upgrades and maintenance without service impact through traffic draining and staged rollouts.
• Troubleshoot complex Layer 1–7 issues, lead root-cause analysis, and integrate firewalls, load balancers, and security controls.
• Build network automation, monitoring, and streaming telemetry; produce designs, runbooks, and change documentation.

Requirements

• Experience designing, building, and operating datacentre networks.
• Knowledge of Cisco and Arista technologies, spine-leaf architecture, and VXLAN/EVPN.
• Experience with BGP, OSPF or IS-IS, ECMP, fast failover, MLAG/vPC, and LACP.
• Ability to troubleshoot across Layers 1–7 and lead root-cause analysis.
• Experience with network automation using Python, Ansible, and CI/CD pipelines.
• Experience implementing monitoring, streaming telemetry, and integrating firewalls, load balancers, and security controls.

Nice to have

• Background in financial markets environments.
• Interest in broader client-focused consulting work and professional and technical development.

Culture & Benefits

• Permanent position with hybrid working in London.
• Bonus and training provided.
• Opportunity to work in a growing datacentre transformation consultancy.
• Role suitable for experienced datacentre engineers and engineers at the beginning of their datacentre careers.