OT Architect

Key Responsibilities

• · Own current-state, transition and target-state OT security architecture workstreams. · Lead architecture discovery, requirements and design workshops with OT engineers, IT teams, vendors and technology stakeholders. · Design network segmentation, zones and conduits, IT/OT boundaries, secure remote access and access control models. · Produce clear, auditable architecture artefacts, including principles, requirements, HLDs, LLDs, network diagrams, data flows, firewall rule specifications and bills of materials. · Assess technology options and translate operational, safety and security needs into pragmatic design decisions. · Provide hands-on technical assurance during implementation, testing and acceptance. · Contribute to practice development, reusable methodologies, proposals and the development of junior colleagues. Location and travel This is a UK-based hybrid role, with travel to national client sites expected for approximately 20% of the time. International travel or support may also be required by agreement.
• · Own current-state, transition and target-state OT security architecture workstreams. · Lead architecture discovery, requirements and design workshops with OT engineers, IT teams, vendors and technology stakeholders.
• · Design network segmentation, zones and conduits, IT/OT boundaries, secure remote access and access control models. · Produce clear, auditable architecture artefacts, including principles, requirements, HLDs, LLDs, network diagrams, data flows, firewall rule specifications and bills of materials. · Assess technology options and translate operational, safety and security needs into pragmatic design decisions. · Provide hands-on technical assurance during implementation, testing and acceptance. · Contribute to practice development, reusable methodologies, proposals and the development of junior colleagues. Location and travel
• This is a UK-based hybrid role, with travel to national client sites expected for approximately 20% of the time. International travel or support may also be required by agreement.

Skills, Knowledge & Expertise

Job Benefits

Skills

• What we are looking for
• · Demonstrable experience designing and assuring OT/ICS security architectures in live operational environments. · Strong knowledge of OT architecture patterns, segmentation, zones and conduits, secure remote access, identity and access models, and traffic flow analysis. · Hands-on technical depth across firewalls, switching, routing, virtualisation and security platforms in OT or converged IT/OT environments. · Experience taking architecture from concept through detailed design, implementation support and acceptance. · Working knowledge of IEC 62443, including security levels, foundational requirements and defence-in-depth. · Understanding of OT constraints, including availability, safety, legacy systems and restricted change windows. · Experience in rail, automotive, renewables, manufacturing or comparable OT environments. Useful additional experience
• · OT technologies and protocols, including HMI, PLC, RTU, DCS, SCADA, IEC 61850, DNP3 and Modbus/TCP. · NIST SP 800-82, NIST 800-53, CIS or STIG standards. · Vendor evaluation, procurement support, zero-trust principles or software-defined segmentation in OT. · Relevant certifications such as IEC 62443 Cybersecurity Expert, GICSP, GRID or equivalent.

Qualifications

• What we are looking for
• · Demonstrable experience designing and assuring OT/ICS security architectures in live operational environments.
• · Strong knowledge of OT architecture patterns, segmentation, zones and conduits, secure remote access, identity and access models, and traffic flow analysis.
• · Hands-on technical depth across firewalls, switching, routing, virtualisation and security platforms in OT or converged IT/OT environments.
• · Experience taking architecture from concept through detailed design, implementation support and acceptance.
• · Working knowledge of IEC 62443, including security levels, foundational requirements and defence-in-depth.
• · Understanding of OT constraints, including availability, safety, legacy systems and restricted change windows.
• · Experience in rail, automotive, renewables, manufacturing or comparable OT environments.
• Useful additional experience
• · OT technologies and protocols, including HMI, PLC, RTU, DCS, SCADA, IEC 61850, DNP3 and Modbus/TCP.
• · NIST SP 800-82, NIST 800-53, CIS or STIG standards.
• · Vendor evaluation, procurement support, zero-trust principles or software-defined segmentation in OT.
• · Relevant certifications such as IEC 62443 Cybersecurity Expert, GICSP, GRID or equivalent.