Job Description

The Space, Defence and Intelligence business unit in CGI is a true IT Systems Integrator. We work, build, and operate bespoke, technically complex, mission-critical systems which help our clients keep us all safe and secure. We bring innovation to our clients using proven and emerging technologies, agile delivery processes and our deep expertise across the breadth of space, defence, intelligence, aerospace and maritime, all underpinned by our end-to-end cyber capability. We work collaboratively with global technology companies, cutting edge SMEs and academia to deliver the optimal solution for each client.



CGI was recognised in the Sunday Times Best Places to Work List 2025 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 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. This position will be working out of our site in Cheltenham.

Your future duties and responsibilities

We are seeking a highly skilled and forward-thinking Software Defined Network (SDN) Engineer to spearhead the design, deployment, and optimisation of cutting-edge network infrastructures. In this pivotal role, you will leverage your deep expertise in Cisco ACI and VMware NSX-T to deliver innovative, software-defined solutions across complex hybrid environments. Collaborating closely with cross-functional teams, you will ensure the implementation of robust, scalable, and secure network fabrics that support both on-premises and cloud platforms--driving performance, agility, and resilience across the enterprise



Design, deploy, and manage scalable Software Defined Networking (SDN) architectures using CISCO ACI.


Define and enforce policies and connectivity rules within SDN environments.


Deploy and manage VMware NSX-T for micro-segmentation, distributed firewalling, and advanced routing.


Implement dynamic routing protocols and integration with underlay networks.


Establish security zones and enforce granular access controls through logical segmentation.


Integrate SDN platforms with hybrid infrastructures, including public cloud providers and on-premises data centres.


Collaborate with cloud and systems engineering teams to ensure seamless interconnectivity and performance optimisation.


Diagnose and resolve complex network issues spanning virtual and physical environments.


Use packet capture, flow analysis, and SDN analytics to pinpoint performance bottlenecks and security anomalies.


Provide escalation support and participate in root cause analysis for critical incidents.

Required qualifications to be successful in this role

Proficiency in CISCO ACI fabric design and operations.


Hands-on experience with VMware NSX-T infrastructure setup and security features.


Deep understanding of SDN principles, overlay/underlay concepts, and VXLAN architecture.


Familiarity with cloud networking (AWS, Azure, GCP) and hybrid deployment models.


Solid troubleshooting and diagnostic skills across Layer 2? of the OSI model.


Desirable



Certifications such as Cisco CCNP/CCIE Data Center, VMware VCP-NV, or VCIX-NV.


Knowledge of network automation and orchestration tools (e.g., Ansible, Terraform).


Experience with network monitoring platforms (e.g., vRealize Network Insight, Cisco Nexus Dashboard).


Familiarity with Zero Trust Networking and Network Function Virtualisation (NFV).


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Life at CGI is rooted in ownership, teamwork, respect and belonging. Here, you'll reach your full potential because...



You are invited to be an owner from day 1 as we work together to bring our Dream to life. That's why we call ourselves CGI Partners rather than employees. We benefit from our collective success and actively shape our company's strategy and direction.



Your work creates value. You'll develop innovative solutions and build relationships with teammates and clients while accessing global capabilities to scale your ideas, embrace new opportunities, and benefit from expansive industry and technology expertise.



You'll shape your career by joining a company built to grow and last. You'll be supported by leaders who care about your health and well-being and provide you with opportunities to deepen your skills and broaden your horizons.




Come join our team--one of the largest IT and business consulting services firms in the world.