SDN Engineer: Cisco ACI & NSX-T Secure Hybrid Networks

At CGI, our Space, Defence and Intelligence business unit delivers mission-critical systems that help keep the UK safe and secure.

As a Software Defined Network Engineer, you will play a critical role in designing and delivering next-generation network solutions that enable secure, scalable, and high-performing environments.

Working across complex hybrid infrastructures, you will help drive innovation through software-defined technologies, contributing to impactful programmes. You’ll take ownership of advanced networking solutions, apply creative approaches to complex challenges, and collaborate within a supportive environment that enables continuous growth and meaningful impact.

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.

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 based on site near Gloucester, 5 days a week.

In this role, you will design, deploy, and manage software-defined networking solutions across hybrid environments, ensuring secure, scalable, and high-performing network architectures.

You will take ownership of SDN platforms, working with Cisco ACI and VMware NSX-T to deliver robust connectivity, segmentation, and policy-driven network control aligned to business and technical requirements.

You will collaborate closely with cloud, infrastructure, and security teams to optimise network performance and resilience, while contributing innovative solutions and resolving complex issues.

• Design & Deliver: Build SDN architectures using Cisco ACI and VMware NSX-T
• Configure & Manage: Implement network policies, segmentation, and connectivity rules
• Integrate & Optimise: Support hybrid environments across on-prem and cloud platforms
• Troubleshoot & Resolve: Fix complex issues across Layer 2–7 network layers
• Secure & Enforce: Apply micro‑segmentation and Zero Trust principles
• Collaborate & Align: Work with cloud, infrastructure, and security teams
• Monitor & Improve: Use tooling and analytics to improve network performance

You should have strong hands‑on experience in software‑defined networking, particularly in secure or enterprise environments.

• Proven experience with Cisco ACI and VMware NSX‑T
• Strong understanding of SDN concepts, VXLAN, and overlay/underlay networking
• Experience with hybrid cloud networking (AWS, Azure, or GCP)
• Strong troubleshooting skills across Layers 2–7
• Knowledge of network security, segmentation, and Zero Trust principles
• Familiarity with automation tools (Ansible, Terraform) is beneficial
• Relevant certifications (CCNP/CCIE, VCP‑NV) are desirable