The Senior Cyber Security Engineer (T4) plays a critical role in protecting and enabling mission IT by combining deep technical expertise with pragmatic risk management. You will be able to work with minimal direction on a specific programme, taking responsibility for planning, implementing, and assuring security controls across infrastructure, platforms, and applications (including cloud services). You will provide clear security advice and assurance to stakeholders, typically aligned to HMG/MOD expectations and recognised standards (e.g., NIST, CIS benchmarks), and you will support teams by sharing knowledge and guiding good practice.
Key functions/outputs:
1. Vulnerability Management, Reporting & Risk Prioritisation
2. Endpoint, Identity & Cloud Security Engineering (AWS)
3. Incident Response Leadership & Operational Security
4. Secure Configuration, Hardening & Compliance Assurance
5. Security Design Review, Change Impact Assessment & ST&V
6. Stakeholder Engagement, Governance & Decision Support
7. Documentation, Mentoring & Continuous Improvement
Main Objectives:
Vulnerability Management, Reporting & Risk Prioritisation
Perform regular vulnerability assessments and generate actionable reporting using approved toolsets (or equivalent). The process should focus on ensuring scanners and signatures are current, coverage is agreed, and findings are prioritised based on risk, mission impact, and exploitability. You will support (and where required lead) triage with engineering teams to drive remediation to closure and provide clear risk narratives to senior stakeholders.
- Code Scans: perform regular code scans to assess code quality, detect potential bugs, and identify security vulnerabilities; work with development teams to agree remediation approaches and prevent recurrence.
- Vulnerability Management Tooling: perform regular vulnerability management scans and ensure repositories/plugins are maintained to detect emerging vulnerabilities across endpoints, servers, and cloud workloads.
- Reporting: produce and quality-assure recurring vulnerability and risk reporting for the cyber security and IA lead; highlight trends, systemic issues, and recommendations for control improvements.
Endpoint, Identity & Cloud Security Engineering (AWS):
- Endpoint Protection: drive endpoint security posture through regular updates, policy tuning, and validation activities aligned to current threats and programme requirements.
- Antivirus and Anti-malware Protection: perform assurance checks to ensure controls are deployed successfully, monitored, and kept up to date; define exceptions and compensating controls where needed.
- Network Controls: perform compliance checks and targeted audits of network security controls (e.g., firewall rules, segmentation, proxying) to ensure unauthorised access and threats are blocked and logged appropriately.
- Access Control & IAM: design and ensure access controls are implemented correctly to enforce least privilege and need-to-know across systems and data; provide oversight of privileged access, account lifecycle, and authentication policy.
- AWS Cloud Security: design and assure cloud security controls across networking, identity, logging/monitoring, and configuration management; validate guardrails and support secure landing zone patterns where applicable.
Incident Response Leadership & Operational Security:
- Incident Identification: help to recognise and confirm potential incidents through alerts, logs, and user reports; apply sound judgement to distinguish true threats from false positives.
- Incident Response: lead or provide senior support to containment, eradication, investigation, and recovery activities; coordinate with service owners and stakeholders to restore operations and capture lessons learned.
- Tickets & Requests: manage and resolve tickets raised to the Leidos Security group that require Cyber Security Engineering input; prioritise based on risk and impact, and mentor others through complex issues.
Secure Configuration, Hardening & Compliance Assurance:
- Patch Updates to Security Products: ensure security toolsets are kept up to date with patches and software updates; assess impact and coordinate change implementation in line with governance.
- System Compliance: perform and oversee regular compliance audits to ensure systems meet agreed baselines and best practices (e.g., CIS, STIG, NIST); manage exceptions with evidence-based rationale and compensating controls.
- Security Enforcing Function Configuration: assist in the design, review, and improvement of security enforcing functions (e.g., GPOs, system policies, cloud guardrails) to ensure they are compliant, testable, and fit for purpose.
- Assurance Activities: conduct periodic technical assessments (configuration reviews, control testing, threat-driven checks) to identify weaknesses and drive measurable improvements.
Security Design Review, Change Impact Assessment & ST&V:
- Security Impact Triage Tool (SITT): lead or support evaluation and impact assessment of proposed changes to security posture; provide clear recommendations, conditions, and required evidence for approval.
- Security Evaluation, Testing and Assurance (ST&V): plan and execute security evaluation and assurance activities for changes delivered through PI Planning; define test scope, coordinate evidence capture, and ensure outcomes are documented and traceable.
Stakeholder Engagement, Governance & Decision Support:
Senior Cyber Security Engineers are expected to lead and contribute to governance forums and working groups, providing clear security advice, risk-based recommendations, and decision support. This may include the following depending on work activity.
You will interface with customer security representatives, accreditation/assurance stakeholders, delivery teams, and third-party/supplier engineers to agree security requirements, provide evidence, manage risks and exceptions, and support timely decisions.
- Security Working Group (SWG)
- Customer/Supplier Security Forums
- Vulnerability Triage
- Security Workshop
- PI Planning
- Daily Standups (Blue/Green Team)
Documentation, Mentoring & Continuous Improvement:
Senior Cyber Security Engineers are responsible for creating, maintaining, and reviewing high-quality documentation and security evidence. This includes High-Level & Low-Level Designs (HLD/LLD), Standard Operating Procedures (SOPs), risk assessments, and compliance/assurance reports. You will also support capability uplift through mentoring, knowledge sharing, and identifying opportunities to automate and improve security processes.
- Proven experience in a senior cyber security engineering role, delivering security outcomes across complex IT environments (on-prem and/or cloud).
- Practical experience implementing security as code and policy as code in AWS environments, leveraging tools such as AWS CloudFormation, Terraform, and AWS Organisations service control policies.
- Strong knowledge of secure configuration and hardening practices, and ability to apply benchmarks/standards (e.g., CIS, NIST, STIG) pragmatically.
- Hands-on experience with vulnerability management and risk-based prioritisation, including working with engineering teams to drive remediation.
- Experience supporting or leading incident response activities, including investigation, containment, and lessons learned.
- Ability to communicate technical security issues clearly to non-specialists and support governance/assurance decision-making.
- Experience producing high-quality security documentation and evidence suitable for audit/assurance.
- AWS security-related certifications (e.g., AWS Certified Security – Specialty) or equivalent cloud security experience.
- CISSP, CISM, or equivalent senior-level security certification.
- Degree or postgraduate qualification in cyber security, such as a master’s or PhD in Information Security, Cyber Security, or a related discipline.
Are you ready to make an impact? Begin your journey of a flourishing and meaningful career, share your CV with us today!
What we do for you:
At Leidos we are PASSIONATE about customer success, UNITED as a team and INSPIRED to make a difference. We offer meaningful and engaging careers, a collaborative culture, and support for your career goals, all while nurturing a healthy work-life balance.
We provide an employment package that attracts, develops and retains only the best in talent. Our reward scheme includes:
Contributory Pension Scheme
Private Medical Insurance
33 days Annual Leave (including public and privilege holidays)
Access to Flexible benefits (including life assurance, health schemes, gym memberships, annual buy and sell holidays and a cycle to work scheme)
Flexi-Time
Commitment to Diversity:
We welcome applications from every part of the community and are committed to a truly diverse and inclusive culture. We foster a sense of belonging, welcoming all perspectives and contributions, and providing equal access to opportunities and resources for everyone. If you have a disability or need any reasonable adjustments during the application and selection stages please let us know, and we will respond in a way that best fits your needs.
