Principal Network Engineer

Job Description:

Are you ready to take on complex technical challenges and shape secure networks that underpin the UK's most critical missions? At Leonardo, our Principal Network Engineers are recognised as subject matter experts, providing advanced technical authority and leading the design, integration, and delivery of resilient network solutions.

Your work at Leonardo UK will see you take the lead in solving customer problems in an agile, innovative and team-centric manner. The role may involve a blended hybrid working model, with a mixture of working from home and working on site at one of our locations: Bristol or Gloucester to ensure close collaboration with the wider team and with our customers.

What you will do as a Principal Network Engineer

• Act as the technical authority across one or more networking domains (LAN/WAN, cloud, security, or SDN).
• Lead the design and implementation of secure networks across on-premise, hybrid, and cloud environments.
• Capture and analyse complex requirements, shaping high- and low-level network designs.
• Ensure secure-by-design principles are embedded across all network solutions.
• Own technical delivery within work packages, including planning, estimation, and reporting.
• Provide guidance, mentoring, and technical leadership to junior and senior network engineers.
• Support technology assessments, innovation projects, and roadmap development.
• Engage with customers, stakeholders, and vendors to define and defend technical solutions.

• Extensive technical expertise across multiple networking domains with proven delivery experience.
• Ability to balance hands-on engineering with technical leadership and solution ownership.
• A problem-solving mindset with the ability to innovate and recommend the best approaches for complex challenges.

• Deep understanding of networking protocols and technologies (BGP, OSPF, MPLS, VPNs, QoS, IPsec, MCLAG).
• Experience with Cisco (CCNP level) or equivalent multi-vendor technologies (Dell, Palo Alto, Fortinet).
• Strong knowledge of firewalls, IDS/IPS, and network security principles.
• Experience designing and integrating networks within secure environments.
• Experience with cloud networking (AWS, Azure) and hybrid integration.
• Familiarity with network automation and scripting (Python, Ansible, Terraform).

• Full CCNP or equivalent certification/experience (4-7 years).
• Experience with software-defined networking (SDN, SD-WAN) and cloud-native networking.
• Knowledge of DevSecOps pipelines and integration with security monitoring tools (SIEM, SOC platforms).
• Involvement in industry forums, technical publications, or best-practice development.
• Experience with enterprise IT services (Active Directory, DNS, PKI, monitoring).

This is not an exhaustive list, and we are keen to hear from you even if you might not have experience in all the above. The most important skill is a good attitude and willingness to learn.

This role is subject to pre-employment screening in line with the UK Government's Baseline Personnel Security Standard (BPSS). An additional range of Personnel Security Controls referred to as National Security Vetting (NSV) may apply, this could include meeting the eligibility requirements for The Security Check (SC) or Developed Vetting (DV). For more information and guidance please visit:

This role can be based at one of our UK sites Gloucester, with hybrid/custom working options where appropriate.

At Leonardo, our people are at the heart of everything we do. We offer a comprehensive, company-funded benefits package that supports your wellbeing, career development, and work–life balance. Whether you're looking to grow professionally, care for your health, or plan for the future, we're here to help you thrive.

• Time to Recharge: Enjoy generous leave with the opportunity to accrue up to 12 additional flexi-days each year.
• Secure your Future: Benefit from our award-winning pension scheme with up to 15% employer contribution.
• Your Wellbeing Matters: Free access to mental health support, financial advice, and employee-led networks championing inclusion and diversity (Enable, Pride, Equalise, Armed Forces, Carers, Wellbeing and Ethnicity).
• Rewarding Performance: All employees at management level and below are eligible for our bonus scheme.
• Never Stop Learning: Free access to 4,000+ online courses via Coursera and LinkedIn Learning.
• Refer a friend: Receive a financial reward through our referral programme.
• Tailored Perks: Spend up to £500 annually on flexible benefits including private healthcare, dental, family cover, tech & lifestyle discounts, gym memberships and more.
• Flexible working: Flexible hours with hybrid working options. For part time opportunities, please talk to us about what might be possible for this role.

For a full list of our company benefits please visit our website.

Leonardo is a global leader in Aerospace, Defence, and Security. Headquartered in Italy, we employ over 53,000 people worldwide including 8,500 across 9 sites in the UK. Our employees are not just part of a team—they are key contributors to shaping innovation, advancing technology, and enhancing global safety.

At Leonardo we are committed to building an inclusive, accessible, and welcoming workplace. We believe that a diverse workforce sparks creativity, drives innovation, and leads to better outcomes for our people and our customers. If you have any accessibility requirements to support you during the recruitment process, just let us know.

Be part of something bigger - apply now

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