Senior Network Engineer (DV Security Clearance)

CGI; Chippenham; On-site; GBP 60,000 - 80,000; Full time

Job summary

A leading technology solutions provider in the UK seeks a Senior Network Engineer to enhance and support their critical network infrastructure. The role requires expertise in enterprise and defence-grade networks, with an emphasis on technologies including BGP, VPN, and various firewall systems. You will be responsible for network operations, integration solutions, and mentoring junior engineers while collaborating with expert teams. The position offers a competitive salary and benefits, along with the opportunity for professional growth and development in a diverse environment.

Benefits

Competitive salary

Excellent pension

Private healthcare

Share scheme with matching contributions

Career development support

Qualifications

• Proven experience in a senior network engineering role.
• Strong background in defence environments.
• Expertise with Dell OS10, Sonic, Cisco networking, Palo Alto firewalls, and NSX-T.
• Deep understanding of spine-and-leaf architecture, BGP, VPNs, and data centre patching.
• Strong knowledge of DNS, IPAM, load balancing; F5 and InfoBlox experience desirable.
• Excellent analytical, troubleshooting, and communication skills.

Responsibilities

• Lead advanced support and troubleshooting across multiple networking technologies.
• Contribute to network integration and solution design.
• Manage BGP, VPN, spine-and-leaf architectures.
• Oversee IPAM, DNS and optimize load-balancing solutions.
• Support InfoBlox deployments and align operations with strategies.
• Mentor junior engineers and enhance cross-team collaboration.
• Participate in on-call rota for critical incident resolution.

Skills

BGP

VPN

Dell OS10

Cisco networking

Palo Alto firewalls

NSX-T

DNS

IPAM

Load balancing (F5)

Troubleshooting

Job description

Overview

Position Description : As a Senior Network Engineer at CGI, you will play a pivotal role in safeguarding and advancing the networks that power our clients’ most critical missions. You will help shape resilient, secure, and scalable infrastructure while contributing to innovative integration and design projects that drive industry transformation. This role offers the chance to take meaningful ownership of complex challenges, collaborate with expert teams, and apply your creativity to deliver future-ready network solutions. Supported by CGI’s strong engineering community, you’ll make a lasting impact across high-value programmes while continuously growing your skills in a dynamic and trusted environment.

CGI was recognised in the Sunday Times Best Places to Work List and has been named a UK ‘Best Employer’ by the Financial Times. We offer a competitive salary, excellent pension, private healthcare, plus a share scheme (3.5% + 3.5% matching) which makes you a CGI Partner not just an employee. We are committed to inclusivity, building a genuinely diverse community of tech talent and inspiring everyone to pursue careers in our sector, including our Armed Forces, and are proud to hold a Gold Award in recognition of our support of the Armed Forces Corporate Covenant. Join us and you’ll be part of an open, friendly community of experts. We’ll train and support you in taking your career wherever you want it to go.

Due to the secure nature of the programme, you will need to hold UK Security Clearance or be eligible to go through this clearance.

Your future duties and responsibilities

In this role, you will take ownership of complex network operations, ensuring high availability, stability, and security across critical infrastructures. You will apply your expertise to both support and enhance network environments, driving improvements that strengthen operational resilience and client outcomes. Working closely with multidisciplinary teams, you will contribute to the design and integration of new solutions, using your creativity and judgement to deliver scalable, future-proof capabilities.

You will also play a key role in knowledge sharing and team development, offering guidance to colleagues while being supported by a collaborative engineering community. Your decisions and insights will directly influence service quality, network performance, and the success of mission-critical programmes.

Key Responsibilities

• Lead & Innovate: Provide advanced support and troubleshooting across Dell OS10, Sonic, Cisco, Palo Alto, and NSX-T technologies.
• Develop & Deliver: Contribute to network integration, solution design, and scalable infrastructure enhancements.
• Optimise & Automate: Manage BGP, VPN, spine-and-leaf architectures, and data centre patching to maintain high performance.
• Maintain & Enhance: Oversee IPAM and DNS, and optimise load-balancing solutions, particularly F5.
• Integrate & Secure: Support InfoBlox deployments and align network operations with wider infrastructure strategies.
• Collaborate & Guide: Mentor junior engineers and strengthen cross-team engagement.
• Support & Protect: Participate in the on-call rota to ensure fast, effective resolution of critical incidents.

Required qualifications to be successful in this role

To excel in this role, you should bring strong technical depth in enterprise and defence-grade networks, combined with the ability to troubleshoot, design, and integrate complex solutions. You should be confident working in high-availability environments and comfortable collaborating across teams to deliver secure, high-impact outcomes.

Essential Qualifications :

• Proven experience in a senior network engineering role.
• Strong background in defence environments.
• Expertise with Dell OS10, Sonic, Cisco networking, Palo Alto firewalls, and NSX-T.
• Deep understanding of spine-and-leaf architecture, BGP, VPNs, and data centre patching.
• Strong knowledge of DNS, IPAM, load balancing; F5 and InfoBlox experience highly desirable.
• Excellent analytical, troubleshooting, and communication skills.

Desired Qualifications :

• Understanding of cross-domain technologies (Tiger Traps, Garrison, OpsWat, NiFi).
• Familiarity with VMware infrastructure and Elastic monitoring.