OT Network Security Engineer

Location: Hybrid in Glasgow, Dundee, or Aberdeen, Scotland, United Kingdom

Company

Provides technology services supporting critical national infrastructure, energy, public sector, and enterprise organisations through managed services, cybersecurity, cloud, data, AI, and digital transformation.

What you will do

• Design and implement secure OT network architectures, including firewalls, switches, routers, and secure remote access solutions.
• Implement segmentation between IT, OT, and safety-critical environments, including industrial DMZs, security zones, and conduits.
• Configure VLANs, routing, access controls, firewall policies, VPNs, and network security controls.
• Support migrations, upgrades, infrastructure refreshes, testing, validation, FAT, SAT, commissioning, and production go-live activities.
• Troubleshoot network, connectivity, and firewall issues and support hardening, vulnerability remediation, and security improvements.
• Produce network designs, diagrams, firewall rule sets, test plans, and as-built documentation while advising customers on OT network security and resilience.

Requirements

• Strong hands-on experience with enterprise and industrial networking and next-generation firewalls.
• Experience with Palo Alto Networks, Fortinet, Cisco, or Check Point, including firewall policies, NAT, VPNs, IPS/IDS, and application-based security controls.
• Experience designing OT network segmentation and industrial DMZs; strong knowledge of VLANs, routing, switching, TCP/IP, DNS, and network services.
• Experience with Cisco switching and routing, secure remote access, privileged OT connectivity, industrial protocols, monitoring, packet analysis, and troubleshooting tools.
• Experience with high availability, redundant networks, resilient architectures, network testing, validation, acceptance activities, and technical documentation.
• Understanding of network access control, identity-based access, and zero trust principles.

Nice to have

• Experience in OT, industrial, energy, utilities, or critical national infrastructure environments.
• Knowledge of IEC 62443, the Purdue Model, NCSC CAF, NIST, or other OT security frameworks.

Culture & Benefits

• Hybrid work arrangement across Glasgow, Dundee, or Aberdeen.
• Work on complex challenges with real-world impact for critical infrastructure and public-facing organisations.
• Collaborate with OT, cybersecurity, infrastructure, application, and engineering specialists.