Senior Network Engineer - Active UK Government Security Clearance Required

Location: UK - Hybrid / customer-site requirements TBC

Contract: Permanent, Full-time

Package: £75,000 - £85,000 + 10% Bonus + 10% Shares + Benefits

About Appvia

Appvia is a specialist cloud, platform, and solutions engineering consultancy, helping organisations modernise infrastructure, improve reliability, and adopt cloud-native practices that enable long-term, sustainable delivery.

Our engineering capability spans AWS, Azure, platform engineering, networking, software, data, AI, delivery, and managed services.

We work across complex, high-impact environments in both the public and private sector, delivering solutions where security, resilience, scalability, and operational excellence are critical.

About the Role

We're hiring a Senior Network Engineer to join Appvia on a new secure public sector engagement, taking a lead role in a significant Cisco SD-WAN migration and transition programme.

This is a senior, hands-on role with real ownership: you'll take the lead on complex network changes and migration activity, peer review network designs produced by others, gather and analyse network requirements, and directly support senior architects in preparing material for formal design and security governance boards. You'll also coach and mentor more junior network engineers as part of building out the wider team's capability.

This role sits above our Network Engineer role in seniority - where that role focuses on implementing and supporting designed network services, this role owns migration workstreams end-to-end, reviews the work of others, and takes on a mentoring and technical leadership responsibility within the team.

Interview Process - 3 Stage

1. Discovery conversation with Talent Acquisition
2. Technical Interview with Engineering Team
3. Final Interview with Leadership

Important

You must hold active UK Security Clearance (SC). NPPV3 clearance is highly desirable.

Requirements

About You

You are an experienced Senior Network Engineer with strong Cisco networking fundamentals, comfortable taking ownership of complex network migration work, reviewing the designs of others, and mentoring more junior engineers.

You will bring:

• CCNA certification, or demonstrable equivalent knowledge of networking concepts, switching, routing, firewalling, and load balancing
• Cisco SD-WAN experience, including the use of BGP
• Strong experience designing, implementing, and supporting enterprise network environments
• Experience with IPv4/IPv6 migration, particularly migrating from legacy/private network connectivity to internet-based, SD-WAN-enabled connectivity
• Experience owning and leading migration projects, such as moving between hosting providers or from legacy to modern network infrastructure
• Experience troubleshooting complex production networking issues and leading root-cause analysis
• Experience working in live service, operational, or managed-service environments, including incident management
• Experience with network testing and test planning
• Experience with systems installation and removal
• Confidence producing, reviewing, and peer-reviewing network designs and technical documentation
• Experience supporting the preparation of material for formal design or security governance boards
• Coaching and mentoring more junior network engineers, including contributing to appraisal and performance management processes
• Strong stakeholder communication and consulting skills, building effective partnerships across diverse teams, locations, and technologies
• Understanding of how trends and practices outside your team affect your work and the broader delivery context
• Formal training in computer science to degree level, or equivalent industry experience
• Active UK SC clearance

Responsibilities

• Review and provide peer review advice on network designs produced by other engineers
• Take ownership of migration and transition workstreams from planning through to delivery
• Directly support senior architects in preparing material for formal design and security governance boards
• Gather and analyse network requirements, including bandwidth, latency, fault tolerance, and access control needs
• Own complex network incidents, troubleshooting, and root-cause analysis
• Lead planned network changes, upgrades, migrations, and optimisation activities, including IPv4/IPv6 migration work
• Design and support routing, switching, firewalling, VPN, and load-balancing solutions
• Carry out systems installation and removal as part of network change activity
• Support and plan network testing activities
• Evaluate the success of delivered projects, identifying best practice and lessons learned, and feeding this back into future work
• Contribute to high-level and low-level network designs and technical documentation
• Monitor and improve network availability, performance, resilience, and security
• Coach and mentor junior network engineers, providing technical guidance and supporting their development and appraisal
• Work closely with engineering, service management, architecture, and customer teams

Technical Skills

Core technologies / experience:

• Cisco SD-WAN
• CCNA or equivalent demonstrable knowledge of networking concepts, switching, and routing
• BGP (Border Gateway Protocol)
• Firewalling
• Load balancing
• IPv4/IPv6 migration
• Incident management
• Network testing / test planning
• Systems installation and removal
• Enterprise networking in high-availability production environments

Nice to have:

• Cloud networking experience (AWS or Azure)
• Infrastructure-as-code and automation (e.g. Terraform, Ansible, Python)
• Cisco ACI / Nexus
• OSPF / MPLS / VLANs / VRFs
• Firewalls such as Palo Alto or Check Point
• VPN / IPSec
• Netscaler / F5 / VMware NSX
• CCNP / CCIE or equivalent
• NPPV3 clearance

Benefits

Why join Appvia?

We are a self-funded, London based startup; providing businesses with a fast and secure way to deploy containerised applications into the cloud.

We are on a mission to enable organisations to make cloud-based software delivery simple and efficient, whilst having the insights into costs, security and cadence. As a company that holds customers at the heart of everything we do, we are looking for candidates that want to make a real change to how Dev and Ops is working in the industry.

With us our customers, like the UK’s Home Office & Bank of England, are harnessing cloud-native technologies, limiting the challenges of infrastructure management and rapidly delivering digital products.

What’s on offer?

⚖️ Work-life balance

• Flexible working with core hours of 10-4pm because we know life happens outside of work
• Hybrid working - only one compulsory office day per month
• 25 days’ holiday a year, plus bank holidays
• An additional day off for your birthday
• Enhanced maternity and paternity to full pay
• Workplace Nursery Benefit to help working parents

💚 For your well-being

• Full Private Healthcare cover for you with partners and children covered 50%
• Death in Service
• Cycle to Work scheme
• Electric Car Scheme
• Pension plus a salary sacrifice option for even greater savings
• Employee Assistance Programme
• Free hygiene products available in the London office

🧠 Mental health support

• Free therapy through AXA
• Access to the Headspace App
• Trained Mental Health First Aiders

😃 Other fun perks

• Learning budget of £1,000 a year
• Your own MacBook Pro while you work at Appvia
• Dog friendly office
• Wear what makes you comfortable
• Free snacks in the office
• Regular team socials, board game nights, industry meetups and more!
• Pool table & ping pong table

But don’t just take our word for it, you can check out what our Appvians say about us on Glassdoor and by following us on LinkedIn, Twitter and TikTok.

We are proud to be an equal opportunities employer and actively encourage, respect, and recognise diversity of thought and background throughout the business. All applicants will be considered for employment without attention to age, ethnicity, religion, sex, sexual orientation, gender identity, family or parental status, national origin, or veteran, neurodiversity, and disability status.

Note: While all roles are active and approved at the time of posting, the dynamic nature of our start-up means some applications may be processed to pipeline talent for future opportunities rather than current openings. We will strive to keep you informed of any changes to the status of your application.

As a condition of employment, all successful candidates are required to complete Appvia's standard pre-employment checks, including right-to-work verification and reference checks, and to agree to Appvia's confidentiality and data handling policies as part of their employment terms. Screening for this role is carried out in line with UK Government vetting standards and Appvia's Information Security Management System.