Senior Classified Systems Security Engineer

Lockheed Martin Corporation; England; On-site; GBP 70,000 - 110,000; Full time

Job summary

Lockheed Martin Corporation in the United Kingdom seeks an Information Security Engineer to own security engineering, accreditation, and lifecycle assurance of classified IT systems, ensuring compliance with UK Government, MoD, and Lockheed Martin security requirements.

You will work closely with programme teams, architects, accrediting authorities, and information assurance stakeholders to ensure security is embedded throughout the system lifecycle and to support continuous improvement of

Qualifications

• Strong understanding of Microsoft Windows Server, Linux operating systems, virtualisation technologies, and enterprise networking.
• Experience securing classified, air-gapped, or highly regulated IT environments.
• Knowledge of cloud security principles including AWS, IaaS, and PaaS technologies where applicable.
• Familiarity with security technologies including endpoint protection, SIEM, vulnerability management, encryption, and identity management solutions
• Demonstrable experience applying Secure by Design principles in complex IT systems and programmes.
• Experience conducting security architecture reviews, threat modelling, and risk assessments.
• Strong understanding of system hardening, security controls implementation, and security testing methodologies.
• Experience supporting system engineering and security requirements management within regulated environments.
• Proven experience developing accreditation evidence and security assurance documentation.
• Experience obtaining and maintaining Authority to Operate (ATO) approvals for classified or regulated systems.
• Knowledge of UK Government and MoD accreditation processes and assurance frameworks.
• Experience working directly with accrediting authorities, security controllers, or customer assurance organisations.
• Excellent written and verbal communication skills.
• Ability to communicate technical security concepts to both technical and non-technical stakeholders.
• Strong analytical and problem-solving skills.
• Ability to work independently while supporting multiple programmes and stakeholders.
• CISSP, CISM, or equivalent Information Assurance certification.
• Degree in Cyber Security, Information Security, Computer Science, Engineering, or a related discipline.
• Experience within Defence, Aerospace, Government, or National Security sectors.
• Knowledge of UK Government Security Policy Framework (SPF), NCSC guidance, JSP 440, and Defence security requirements.
• Understanding of GDPR and UK Data Protection Act requirements where applicable.
• Ability to obtain and maintain UK Security Check (SC) clearance with willingness and eligibility to achieve Developed Vetting (DV) clearance.
• Occasional UK and EMEA travel may be required.

Responsibilities

• Lead the implementation of Secure by Design principles across classified IT systems and projects.
• Provide security engineering expertise throughout the system development and operational lifecycle, ensuring security requirements are identified and implemented from concept through disposal.
• Conduct security architecture reviews, threat assessments, and technical risk analysis for classified environments.
• Support the development and maintenance of system security documentation, security architectures, and security operating procedures.
• Lead and coordinate system accreditation activities for classified and sensitive systems.
• Develop and maintain accreditation artefacts including RMADS, Security Cases, Security Management Plans, and supporting evidence.
• Work with Accreditors, Security Controllers, and customer security representatives to obtain and maintain Authority to Operate (ATO) approvals.
• Ensure continued compliance with applicable regulatory, contractual, and customer security requirements throughout system operation.
• Identify, assess, and mitigate cybersecurity risks within classified IT environments.
• Conduct security assessments, vulnerability reviews, and compliance audits against corporate and government security standards.
• Support risk treatment planning and remediation activities.
• Ensure alignment with SPF, NCSC, JSP 440, and Defence security policies and standards where applicable.
• Support incident response investigations affecting classified systems.
• Assist with vulnerability management, patch management, and security monitoring activities.
• Participate in security reviews and technical investigations to identify root causes and corrective actions.
• Provide technical guidance to system administrators and engineering teams on security controls and best practices.
• Collaborate with programme managers, solution architects, IT teams, information assurance practitioners, and customer representatives.
• Provide security guidance to project teams during system design, implementation, and operational support phases.
• Support customer and regulatory audits and inspections.

Skills

Windows Server

Linux OS

Virtualisation

Enterprise Networking

Security in regulated environments

AWS security

Endpoint protection

SIEM

Vulnerability management

Encryption

Identity management

Secure by Design

Security architecture reviews

Threat modelling

Risk assessments

System hardening

Security controls

Security testing

Requirements management in regulatedEn

Education

CISSP or CISM certification

Degree in Cyber Security/Information Security/CS/Engineering

Job description

Lockheed Martin Corporation in the United Kingdom seeks an Information Security Engineer to own security engineering, accreditation, and lifecycle assurance of classified IT systems, ensuring compliance with UK Government, MoD, and Lockheed Martin security requirements.

You will work closely with programme teams, architects, accrediting authorities, and information assurance stakeholders to ensure security is embedded throughout the system lifecycle and to support continuous improvement of