Network Engineers in London

CGI was recognised in the Sunday Times Best Places to Work List and has been named one of the ‘World’s Best Employers’ by Forbes magazine. We offer a competitive salary, excellent pension, private healthcare, plus a share scheme (3.5% + 3.5% matching) which makes you a member 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.

CGI’s Space, Defence and Intelligence business unit focuses primarily on the delivery of contemporary and innovative technical solutions for the government agencies' most challenging problems. We work, build, and operate bespoke, technically complex, mission-critical systems which help our clients keep us all safe and secure. We are currently looking for experienced cloud engineers to join our cross-functional team who, in partnership with our clients, will help define, guide and assure the delivery of integrated solutions. The role offers fantastic opportunities to work within an interesting and highly rewarding environment. We are heavily committed to developing our members and provide excellent learning and development opportunities to ensure that your knowledge and skills keep pace with the evolving technology landscape. We engender a culture of innovation, collaboration and ownership; highly motivated self-starters thrive within our organisation.

Due to the secure nature of this project, this role requires candidates to either already hold, or be eligible to obtain, a high level of UK Security Clearance. To meet the eligibility criteria for this clearance, applicants must be sole British nationals, have been resident in the UK for the past 10 years, and must not have spent more than 28 consecutive days outside the UK within the last five years. Individuals who do not currently hold clearance are still encouraged to apply and will be considered both for this position and for other suitable opportunities within CGI where appropriate.

This role is primarily based on a secure client site and requires attendance on site five days per week due to the sensitive nature of the work and the systems involved. While the position is predominantly site-based, there may be occasional flexibility where business needs and security constraints allow. Any such arrangements would be agreed in advance with the project team.

Your future duties and responsibilities:

In this role, you will provide hands-on expertise to maintain, support, and optimise enterprise network environments that enable critical services. You will take ownership of network stability and performance, working proactively to diagnose issues, implement improvements, and ensure environments remain secure, resilient, and fit for purpose. You will also contribute to network modernisation initiatives, supporting transitions from legacy platforms to more contemporary solutions. Working closely with infrastructure, service management, and application teams, you’ll help deliver controlled change, reduce risk, and continuously improve how network services are delivered.

Key responsibilities include:

• Maintain & Optimise legacy and enterprise network infrastructure to ensure high availability
• Diagnose & Resolve complex incidents across LAN, WAN, VPN, and data centre environments
• Configure & Manage switches, routers, firewalls, and load balancers
• Implement & Control network changes, patching, and upgrades through formal change processes
• Document & Improve network configurations, dependencies, and technical procedures
• Support & Deliver network modernisation and migration activities
• Contribute & Collaborate in incident, problem, and capacity management processes

Required qualifications to be successful in this role:

You will bring strong hands-on experience supporting complex network environments, with the confidence to take ownership of issues and contribute to continuous improvement. You are comfortable working with legacy technologies while supporting transition to modern platforms, and you thrive in collaborative, service-focused environments.

Essential qualifications:

• Proven experience supporting enterprise-scale network infrastructure
• Strong knowledge of LAN, WAN, VPN, and data centre networking
• Hands-on experience with switches, routers, firewalls, and load balancers
• Demonstrated ability to diagnose and resolve complex network issues
• Experience working within structured change, incident, and problem management processes
• Strong documentation skills and attention to detail.