Cyber Security Engineer

Siemens Mobility is seeking an experienced Senior Cyber Security Engineer (Assurance) to support the delivery of critical rail infrastructure and operational technology (OT) solutions across the UK rail network.

This is an excellent opportunity for a cyber security professional with strong experience in Operational Technology (OT), industrial control systems, and security assurance to play a leading role in the delivery of secure rail signalling, control systems, SCADA, electrification, and station technology projects.

Working within Siemens Mobility’s Communications & Information Systems (CIS) business, you will be responsible for providing cyber security leadership throughout the project lifecycle, from bid support and solution architecture through to testing, commissioning, and operational support., As the Senior Cyber Security Engineer, you will:

• Act as the cyber security lead across complex rail infrastructure and OT projects.
• Engage with client security teams to understand security strategies, risk appetite, assurance requirements, and compliance obligations.
• Develop and maintain cyber security requirements throughout the project lifecycle.
• Produce and manage Cyber Security Management Plans, ensuring delivery against agreed timescales, budget, and quality objectives.
• Lead security risk assessments, threat modelling exercises, and mitigation planning.
• Develop secure architectures using zoning and conduit principles to protect critical systems and networks.
• Assess third-party products and components against security requirements.
• Review and approve cyber security evidence and assurance documentation.
• Define security verification and validation strategies, including factory testing, site acceptance testing, and penetration testing activities.
• Support investigation and response activities relating to cyber vulnerabilities and incidents.
• Contribute to continuous improvement initiatives and lessons learned programmes.
• Provide technical leadership, mentoring, and security guidance to project teams and junior engineers.

• Strong cyber security engineering experience within Operational Technology (OT) or industrial control environments.
• Proven experience delivering security assurance on complex engineering or infrastructure projects.
• Practical experience applying the IEC 62443 standards framework.
• Experience performing threat and risk assessments.
• Knowledge of security architecture principles, including network segmentation, zoning, and conduits.
• Experience developing security requirements and assurance artefacts.
• Ability to engage effectively with customers, engineering teams, and senior stakeholders.
• Degree-qualified (or equivalent experience) in Engineering, Computer Science, Cyber Security, or a related discipline.

Desirable Experience

• Knowledge of UK rail systems and infrastructure projects.
• Experience applying CENELEC standards.
• Understanding of:
• NIS / NIS2
• EU Cyber Resilience Act (CRA)
• TS 50701
• Previous experience working within regulated or safety-critical industries such as:
• Rail
• Energy
• Utilities, * CISSP (Certified Information Systems Security Professional)
• CSSLP (Certified Secure Software Lifecycle Professional)
• CCP (CESG Certified Professional)

Rullion celebrates and supports diversity and is committed to ensuring equal opportunities for both employees and applicants.