Network Engineer (L5)

Thorn SDS is a specialist Managed Service Provider based in Alton, Hampshire. We empower technology professionals and organisations across the Space, Defence, and Security sectors — and now, we’re growing our team with a Senior Network Engineer who’s ready to make an impact.

This is a full-time role (5 days per week) based in North Hampshire area but will initially involve occasional travel nationwide for site installation. You’ll be working independently but as part of an integrated delivery team. In terms of seniority you would be operating at a senior engineer level (SFIA Level 5), shaping and supporting mission-critical network infrastructure in highly specialised environments.

Security Clearance

Due to the nature of the work, you must hold – or be eligible to obtain – a high level of National Security Clearance. (See: Gov.UK – United Kingdom Security Vetting)

Some UK travel with overnight stays may be required.

You’ll own and optimise complex network environments, getting hands-on across a wide range of technologies and responsibilities. You will be responsible for network architecture, firewall design and configuration, integration with the existing network infrastructure, connectivity testing, security policy implementation, and production of the associated design and as-built documentation.

The role will span multiple customer projects but will initially be dealing with the replacement of a site-to-site analogue link with a digital IP based solution. This involves developing a low-level network design, associated build and configuration documentation and performing the implementation of these.

• Design Phase:
• Delivery of high-level and low-level network design.
• Contribute to network security approach including firewall considerations and any security zoning inline with site / MoD policy.
• Define network monitoring requirements and solution.
• Build Phase:
• Configure network addressing
• Configure management access controls
• Support security accreditation
• Contribute to test planning and support the test execution.
• Physical installation at site (Firewall, Servers, LAN)
• Contribute to MoD Engineering Change Request documentation.

• Proven experience as a Senior Network Engineer
• Strong capability across most of:
• Routing & Switching
• Network Security including Firewalls
• Network device installation
• Monitoring & Management
• Network Virtualisation
• Network Automation
• Excellent troubleshooting skills and the ability to untangle complex issues
• Certifications such as CCNA / CCNP (or equivalent) are a bonus
• Strong communicator and collaborator
• Analytical mindset with attention to detail
• Ideally, knowledge and experience of MoD Engineering Change Request artefacts

• Competitive salary
• 25 days Annual Leave (plus Bank Holidays) lengthens with years of service.
• Employer Pension Contributions
• Group Life Insurance
• Dental Cashback Plan
• Health Cashback Plan
• Wellbeing Services (includes GP, Physio and Savings Benefits)
• Thorn Wellbeing Support Contribution
• Cycle to Work Scheme
• Supported Training & Personal Development Opportunities
• Octopus EV Salary Sacrifice

Ready to Take the Lead?

If you’re looking to push your career forward in a high-stakes, fast-moving environment, we’d love to hear from you. Join Thorn SDS and become a key player in delivering secure, reliable network solutions where they matter most.

All applicants must have the Right to Work in the UK.

Apply now and shape the future of secure networking.