Senior Network Engineer (Routing & Switching Specialist) - freelance - hybrid, London, UK
London, United Kingdom | Posted on 09/03/2026
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)
Job Description
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.
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
Advantages
- CCIE or CCNP (Routing & Switching or Data Centre)
- Automation/scripting experience (Python, Ansible, or similar)
- Experience in financial services or similarly regulated environments
- 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
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