Security Architect - OT - Operational Technology

Around £650/d - Outside IR35

Hybrid working with 2-3 days onsite in Preston

6 months initially, with possible extensions due to the long-term nature of the programme.

Active SC Cleared required

An exciting opportunity has arisen with a highly recognised organisation in the defence sector, focused on transforming and modernising military and security infrastructure through data-driven digital transformation, battlefield management systems, and advanced cybersecurity.

ABOUT THE ROLE

In this role you will be joining a bigger team of Security Architects delivering secure, mission-critical systems across the IT/OT environment for a defence client based in Preston.

You will be responsible for defining, designing, and governing the architecture of industrial and operational systems that control and monitor physical processes. The role ensures OT environments are secure, and acting as a technical authority across Industrial Control Systems (ICS), SCADA, and IIoT. You will provide strategic direction alongside hands‑on architectural leadership.

WHAT WILL YOU DO?

OT Architecture & Strategy

• Support long-term OT roadmaps, modernization initiatives, and IT/OT convergence
• Define and maintain OT architecture principles, standards, and reference designs
• Design end-to-end OT solutions covering control systems, networks, data flows, and integrations
• Ensure architectures meet safety, availability, and operational resilience requirements
• Architect solutions across ICs, SCADA, DCS, PLCs, and HMIs
• Review designs, vendor solutions, and system changes for architectural compliance
• Produce clear architecture documentation, standards, and guidanceSupport integration of OT systems with enterprise IT, cloud, and data platformsDefine standards for industrial protocols (e.g., Modbus, OPC UA, DNP3, IEC 61850)Embed security-by-design into OT architecturesDefine OT network segmentation, zoning, and access controls (Purdue Model / IEC 62443)Conduct risk assessments, threat modeling, and architecture assurance reviewsSupport compliance with safety and security regulations and standards

WHAT DO YOU NEED TO BE SUCCESFUL?

• Proven experience as an Architect in complex environments
• Strong experience with IT/OT environments and industrial control system architectures
• Understanding of OT cyber security principles and standards
• Experience with ICs/SCADA/DCS environments
• Knowledge of industrial networking and protocols
• Understanding of IT/OT integration and data flows
• Proven experience as an Architect in complex environments
• Previous experience working on MOD and defence project is desired, but not essential