Ot Security Architect

Southern Water; England; On-site; GBP 90,000 - 130,000; Full time

Job summary

Southern Water seeks an experienced OT Security Architect to lead secure OT design and governance across its operations. You will shape architectures for SCADA, PLC, DCS, HMI and IIoT, assess cyber risk and embed security-by-design across major programmes.

Working with engineering, IT and cyber security teams, you will apply IEC 62443, NIST 800-82, ISO 27001 and NIS2 to deliver secure, resilient industrial control environments while enabling operational innovation.

Qualifications

• Extensive OT security experience across industrial environments.
• Deep knowledge of SCADA, DCS, PLC, RTU, HMI and historian tech.
• Strong grasp of OT security frameworks (IEC 62443, NIST 800-82, ISO 27001, NIS2).
• Ability to translate complex security concepts to diverse audiences.

Responsibilities

• Design and maintain OT security architectures, standards and frameworks.
• Lead OT security risk assessments and ensure regulatory compliance.
• Define secure integration patterns between OT and IT environments.
• Provide threat modelling and security design assurance for major programmes.
• Support incident response planning, resilience testing and recovery strategies.
• Collaborate with engineering, IT and cyber security teams to embed security-by-design.

Skills

OT security

SCADA security

Zero Trust

IEC 62443

NIST 800-82

Communication skills

Tools

Vulnerability management tools

Threat detection platforms

Job description

We're looking for an experienced OT Security Architect to lead the design and governance of secure Operational Technology (OT) environments across our business. This is a unique opportunity to work at the forefront of cyber security, engineering and digital transformation, safeguarding industrial control systems while enabling innovation across our operational sites. What will you be doing? As our OT Security Architect, you'll play a pivotal role in ensuring the security and resilience of our industrial control systems, SCADA platforms, automation networks and connected operational technologies. Working closely with engineering, IT, cyber security and operational teams, you'll define secure architectures, manage cyber risk and embed security-by-design principles across major programmes and projects.,

• Designing and maintaining OT security architectures, standards and frameworks.
• Developing secure solutions across SCADA, PLC, DCS, HMI, historian, IIoT and edge environments.
• Creating secure network designs incorporating segmentation, firewalls, DMZs and Zero Trust principles.
• Leading OT security risk assessments and ensuring compliance with standards including IEC 62443, NIST 800-82, ISO 27001 and NIS2.
• Supporting IT/OT convergence initiatives and defining secure integration patterns between operational and enterprise environments.
• Providing expert guidance, threat modelling and security design assurance for projects and programmes.
• Supporting cyber incident response planning, resilience testing and recovery strategies.

You’ll bring a strong background in OT or industrial cyber security, combined with the ability to influence stakeholders and drive secure outcomes across complex operational environments.

You’ll ideally have:

• Extensive experience securing OT, IC
• Strong knowledge of SCADA, PLC, DCS, RTU, HMI and historian technologies.
• Experience designing secure OT networks, including zoning, segmentation, firewalls and DMZ architectures.
• Knowledge of industrial protocols such as OPC-UA, Modbus, PROFINET, Ethernet/IP, BACnet and DNP3.
• Strong understanding of OT cyber security frameworks including IEC 62443, NIST 800-82, ISO 27001 and NIS2.
• Experience with vulnerability management, threat detection, monitoring tools and secure remote access solutions.
• The ability to communicate complex technical concepts to both technical and non-technical audiences.

Desirable

• Professional certifications such as CISSP, GICSP, TOGAF, SABSA or ISA/IEC 62443.
• Experience working in critical national infrastructure, regulated industries or safety-critical environments.
• Exposure to cloud-connected OT environments, edge computing or IIoT platforms.