Principal Network Engineer - ISPPermanent | £80,000pa - £90,000pa + Benefits | London HQ - Hybrid Role - 2 Days per Week at HQLocation is London. Candidates located across the UK Midlands, London and South East UK will be considered, provided they can attend the London HQ two days per week.The Opportunity:Surfing a wave of success in 2026, my client is offering an experienced Principal Network Engineer this exciting opportunity to lead the architecture, design, delivery and optimisation of large-scale carrier-grade networks.You will act as the Senior Technical Authority across Network Infrastructure Projects, providing expert guidance, Technical Leadership, Network Architecture and Network Design as well as final-level/4th level escalation support.Applicants should have experience working for an ISP or closely with Internet Service Providers/PON''s within a carrier-grade environment.CCIE and/or CCIP Certifications are highly advantageous, but not essential if you have proven experience ie gained battle scars in the Networking and ISP arena.Key Requirements:Proven expertise in Network Architecture and Network Design (essential).Experience working for an ISP or within an ISP/carrier-grade network environment (essential).Advanced Cisco networking experience across enterprise and service provider technologies.CCIE (Service Provider or Enterprise preferred) highly desirable; candidates able to demonstrate CCIE-level capability will also be considered.Strong knowledge of BGP, ..... full job details .....