Principal Network Engineer - Internet Service Provider

Looking for a role with plenty of growth opportunities?

Join a growing full-fibre broadband provider delivering high-speed connectivity to businesses across London. The organisation is focused on providing reliable, gigabit-capable network services that support businesses of all sizes with modern digital infrastructure.

This opportunity is for a Principal Network Engineer to lead the architecture, implementation and ongoing development of a large-scale Cisco-based service provider network. Acting as a senior technical authority, the role involves leading network projects, shaping strategic infrastructure development, and providing expertise on complex routing and network challenges.

If you would like to learn more about this opportunity, feel free to reach out and apply today!

Responsibilities:

• Design, develop, and optimise the ISP core network to ensure scalability, resilience, and performance.
• Lead the technical design and delivery of network expansion and transformation projects.
• Develop and maintain high and low-level network designs and implementation plans.
• Provide expert-level support and troubleshooting for complex network issues and major incidents.
• Act as a senior escalation point for routing, switching, and service provider network challenges.
• Work closely with operational teams to ensure network stability and continuous improvement.
• Contribute to capacity planning, network strategy, and future technology adoption.
• Maintain technical documentation, standards, and best practices across the network estate.
• Support mentoring and knowledge sharing within the engineering team.

Required Skills/Qualifications:

• Extensive experience working within an ISP, telecommunications, or service provider environment.
• Strong background designing and supporting carrier-grade core networks.
• Expert knowledge of:
  • BGP
  • MPLS
  • Unicast routing technologies
• Significant experience designing, implementing, and troubleshooting large-scale routing infrastructures.
• Strong understanding of network architecture and service provider design principles.
• Hands-on experience with Cisco networking technologies in enterprise or service provider environments.
• Proven ability to deliver complex network projects from design through to implementation.

Desirable Skills:

• CCIE certification (Service Provider, Enterprise Infrastructure, or equivalent).
• Experience operating within large-scale carrier or wholesale ISP networks.
• Exposure to modern service provider technologies and network automation tools.
• Strong technical problem-solving and analytical skills.
• Comfortable operating as a senior technical lead and subject matter expert.
• Able to work independently whilst collaborating effectively across teams.
• Strong communication skills with the ability to explain technical concepts to a range of stakeholders.
• Proactive approach to ownership, delivery, and continuous improvement.

Benefits:

• This is an opportunity to play a key role in shaping and developing a carrier-grade Cisco network environment. You'll have significant influence over network design decisions, work on major infrastructure projects, and be part of a team responsible for delivering highly resilient services at scale.

Salary:

• Competitive salary based on experience and qualifications