Senior Core Network Engineer Cisco & Automation Lead

Oscar; England; On-site; GBP 100,000 - 130,000; Part time

Job summary

Oscar is seeking an experienced Senior Core Network Engineer to support a large-scale enterprise network in London, Chester or Bromley. The role requires deep Cisco IOS-XR expertise, network automation, and delivering major infrastructure programmes.

You will design, implement and migrate core network components, lead hardware refreshes, and develop automation using Cisco NSO and modern tooling. Candidates with CCNP/CCIE and IaC experience are preferred.

Qualifications

• Extensive experience engineering enterprise/service provider core networks.
• Strong expertise with Cisco IOS-XR.
• Hands-on experience with Cisco NSO and network automation.
• Proficient in MPLS, SR-MPLS, BGP, OSPF and ISIS.
• Experience with Cisco 8000, ASR9000 or NCS platforms.
• Knowledge of WAN and optical networking.
• Experience with Python, YANG, NETCONF or REST APIs.
• Proven experience delivering large-scale migrations and upgrades.
• CCNP or CCIE certification.
• Infrastructure as Code using Terraform or Ansible.
• Experience in regulated/financial services environments.
• Knowledge of cloud networking/DevOps/Arista technologies.

Responsibilities

• Design and optimise large-scale core network infrastructure.
• Lead network transformation programmes and hardware refreshes.
• Deliver end-to-end migration activities with planning and rollback.
• Build network automation using Cisco NSO and modern tools.
• Support routing, switching and optical networking globally.
• Produce documentation, standards and implementation plans.
• Collaborate with architecture, operations and project teams.
• Troubleshoot complex networking issues and drive service improvements.

Skills

Cisco IOS-XR

NSO & automation

MPLS

SR-MPLS

BGP

OSPF

ISIS

Cisco platforms

Network automation

Python

YANG

NETCONF

REST APIs

Terraform

Ansible

Cloud networking

DevOps practices

CCNP/CCIE

Regulated environments

Arista technologies

Education

Cisco CCNP or CCIE certification

Tools

Cisco NSO

Terraform

Ansible

YANG

NETCONF/REST APIs

Job description

Oscar is seeking an experienced Senior Core Network Engineer to support a large-scale enterprise network in London, Chester or Bromley. The role requires deep Cisco IOS-XR expertise, network automation, and delivering major infrastructure programmes.

You will design, implement and migrate core network components, lead hardware refreshes, and develop automation using Cisco NSO and modern tooling. Candidates with CCNP/CCIE and IaC experience are preferred.