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# Senior Core Network Engineer

- **Company:** Oscar Associates Ltd
- **Location:** Greater London, UK
- **Experience:** Expert
- **Salary:** £117,000.0 - £120,900.0
- **Contract:** Temporary contract
- **Skills:** Border Gateway Protocol, Cisco IOS, Cloud Computing, DevOps, Multi-protocol Systems, Python (Programming Language), Network Troubleshooting, Netconf, Routing, Open Shortest Path First (OSPF), Ansible, Computer Network Technologies, Restful APIs, Terraform, Open Network Automation Platform, Cisco
- **Published:** September 5, 2026
- **Apply:** https://www.careerboard.com/pt/en/find-jobs-in-United-Kingdom/-20E5F5DAD097D9A68C/

## About the Role

* Extensive experience engineering enterprise or service provider core networks.
 * Strong expertise with Cisco IOS-XR.
 * Hands-on experience with Cisco NSO and network automation.
 * Excellent knowledge of MPLS, Segment Routing (SR-MPLS), BGP, OSPF and ISIS.
 * Experience with Cisco 8000, ASR9000 or NCS platforms.
 * Strong understanding of WAN and optical networking technologies.
 * Experience with Python, YANG, NETCONF or REST APIs for network automation.
 * Proven experience delivering large-scale network migrations, software upgrades and infrastructure transformation programmes.

Desirable Experience

 * CCNP or CCIE certification.
 * Infrastructure as Code using Terraform or Ansible.
 * Experience within highly regulated or financial services environments.
 * Knowledge of cloud networking, DevOps methodologies or Arista technologies.

## Description

We're seeking an experienced Senior Core Network Engineer to support the evolution of a large-scale enterprise network.

This role would suit an engineer with extensive experience in Cisco core networking technologies, network automation, and delivering large-scale infrastructure projects within enterprise or service provider environments.

What You'll Be Doing

 * Design, implement and optimise large-scale core network infrastructure.
 * Lead network transformation programmes, hardware refreshes and platform upgrades.
 * Deliver end-to-end migration activities, including planning, implementation and rollback strategies.
 * Build and enhance network automation capabilities using Cisco NSO and modern automation technologies.
 * Support routing, switching and optical networking across a global environment.
 * Produce technical documentation, engineering standards and implementation plans.
 * Work closely with architecture, operations and project teams to deliver strategic infrastructure initiatives.
 * Troubleshoot complex networking issues and drive continuous service improvements.


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