Principal Network Engineer

Principal Network Engineer

Role Purpose Principal Network Engineer within the Global Network Engineering team, responsible for delivering a major Internet Gateway Migration programme across the US and UK regions, owning the low-level design and implementation activities. Working closely with other Network engineers, Network Architects, Security Architects, Operations teams, and suppliers, you will design, build, test, migrate, and troubleshoot complex enterprise network services across Internet, WAN, SD-WAN, cloud, and security domains. This is a hands-on network engineering role. Key Responsibilities

• Design, build, test, and implement Internet Gateway migration solutions.
• Configure and troubleshoot complex routing environments including BGP, OSPF, MPLS, VRFs, route redistribution, and traffic engineering.
• Perform deep-dive troubleshooting across Internet edge, SD-WAN, WAN, LAN, cloud, security, and carrier connectivity domains.
• Develop and execute migration plans, implementation procedures, service cutovers, rollback strategies, and operational acceptance testing.
• Perform detailed dependency analysis across routing, security, DNS, DDI, remote access, cloud connectivity, and carrier services.
• Analyse technical dependencies and resolve migration blockers across network and security services.
• Create and review low-level designs, implementation plans, MOPs, and operational documentation.
• Work closely with Network Architects to translate target-state designs into deployable engineering solutions.
• Support and Lead on major implementation events, service transitions, and high-risk change activities.
• Drive engineering best practice, technical quality, and operational readiness.

Required Skills & Experience

• CCIE (Cisco Certified Internetwork Expert) - Enterprise Infrastructure (mandatory)
• Expert-level BGP knowledge including Internet edge design, route policy, traffic engineering, route filtering, and multi-carrier connectivity.
• Extensive hands-on experience with Cisco enterprise routing and switching platforms.
• Proven experience designing and implementing enterprise Internet connectivity solutions.
• Strong SD-WAN engineering experience (Cisco Viptela).
• Strong understanding of OSPF, MPLS, VRFs, QoS, route redistribution, and high-availability network design.
• Experience delivering complex network migrations and transformation programmes.
• Experience integrating enterprise networks with Azure and hybrid-cloud environments.
• Advanced troubleshooting skills using packet captures, protocol analysis, routing diagnostics, and telemetry tools.
• Experience working directly with ISPs, carriers, and managed service providers.
• Experience producing implementation plans, migration runbooks, and low-level designs.

Desirable Skills

• CCDE or equivalent design experience.
• Azure ExpressRoute and hybrid-cloud networking.
• Network automation using tools such as Python, Ansible, NetBrain.
• Experience within Utilities, Energy, Critical National Infrastructure, or highly regulated environments.