Senior Network Engineer (Routing & Switching Specialist) - freelance - hybrid, London, UK

We are committed to building an inclusive workplace and encourage applications from women and other under-represented groups in tech. All qualified candidates are welcome.

Start date: Apr/ May 2026 
Location: London, UK (Hybrid — minimum 2 days per week in office)

We are committed to building an inclusive workplace and encourage applications from all qualified candidates.

Working closely with the Senior Network Architect, this hands-on engineering role is focused on the practical remediation and documentation of a complex, legacy Cisco environment. The successful candidate will be a routing expert capable of diagnosing and unpicking unconventional protocol configurations, building standards-compliant designs, and supporting the convergence of two network environments. Key responsibilities Audit and document the existing network estate (~1,000 devices across both banking entities) Identify and remediate non-standard routing configurations, including atypical EIGRP deployments Define and implement standardised change categories, change risk classifications, and change management templates Support the transition from hybrid ACI to target-state architecture Develop network documentation and operational runbooks Provide detailed input into the network baseline assessment Act as a subject matter expert during change approval board (CAB) reviews Work with managed service providers to ensure designs and standards are followed during implementation. Requirements Must have Expert-level Cisco Routing & Switching: IOS, IOS-XE, NX-OS Hands-on experience with Cisco Nexus platforms (2K, 5K, 7K, 9K) Deep routing protocol knowledge: EIGRP, OSPF, BGP — including troubleshooting of complex or misconfigured environments Familiarity with Cisco ACI and spine-leaf fabric architectures Proficiency with network documentation tools and diagramming Experience working in dual-stack (legacy + modern) environments Understanding of network security segmentation and firewall integration Advantageous CCIE or CCNP (Routing & Switching or Data Centre) Automation/scripting experience (Python, Ansible, or similar) Experience in financial services or similarly regulated environments Soft skills Detail-oriented with a methodical approach to problem diagnosis Able to produce clear, well-structured technical documentation Comfortable working in a fast-paced environment with competing priorities Constructive and collaborative when working with legacy team members and external managed service providers