Comgent

Senior Network Architect - freelance - hybrid, London, UK Contract Comgent United Kingdom Posted On 03/09/2026 Job Information Standard Business working Hours Yes Work Experience 8-10 years City London State/Province City of London N/A Special Considerations Start date: Apr/ May 2026 Location: London, UK (Hybrid - minimum 2 days per week in office) Industry: Financial Services / Banking Job Description A major banking group operating in EMEA is undergoing a significant infrastructure transformation programme, converging two separate network environments (a legacy three-tier Cisco campus network and an ACI spine-leaf fabric) alongside the integration of a European banking subsidiary. This is a hands on senior architecture role requiring both strategic thinking and the ability to roll up sleeves and engage at detailed engineering levels. Requirements Must have Deep expertise in Cisco networking: Nexus (7K, 5K, 2K, 9K), IOS, NX-OS Strong working knowledge of Cisco ACI - ability to assess hybrid/pseudo-ACI deployments and define target-state app-centric or network-centric design Expert level routing and switching: OSPF, BGP, EIGRP (including identification and remediation of misconfigurations) Data centre network design: spine leaf, three tier, convergence strategies Firewall architecture: Palo Alto (PA 40 series), Cisco ASA (legacy and migration) WAN/MPLS concepts and managed service architectures (NTT or similar providers) IP address management (IPAM) and DNS/DHCP strategies Network security design principles Familiarity with SD WAN, cloud networking (Azure, AWS), and hybrid connectivity Advantageous Cisco CCIE (Routing & Switching or Data Centre) or equivalent demonstrable expertise Experience with network automation and orchestration tooling Knowledge of co location and proximity hosting environments Understanding of financial services network requirements (trading floor, market data, payment systems) Able to operate with ambiguity - comfortable in environments without fully defined organisational structure Strong communication skills: able to articulate complex technical problems to non technical senior stakeholders Commercial awareness - understanding of total cost of ownership, vendor contracts, and infrastructure spend Collaborative and pragmatic, with the confidence to challenge incumbents and advocate for sound design principles Self starter capable of providing direction to others with limited supervision