Brian Stephens
Cyber specialist with 20+ years' experience enhancing security maturity across enterprise and Critical National Infrastructure (CNI) environments — architecting, implementing and aligning security and infrastructure controls to measurable frameworks, and delivering risk-based assurance programmes that achieve high-bar certifications such as Cyber Essentials Plus. Translates technical IT and security requirements into measurable, business-aligned outcomes through strong GRC practice, KQL-driven detection and reporting, and stakeholder engagement.
Certifications & clearances
- Active SC Clearance
- DBS Cleared
- Cyber Essentials Certified
- ISO 27001 Implementation
Key skills
Strategic Assurance & GRC
Cloud Security & Identity
Security Operations & Automation
Programme Delivery & Documentation
See the resources page for the standards and frameworks referenced above.
Experience
Cyber Security Assurance Lead
Dec 2024 – CurrentSizewell C Nuclear
- •Established and maintained an audit-ready evidence baseline ensuring compliance with NIST CSF 2.0, ISO 27001 and ONR SyAPs.
- •Delivered Cyber Essentials Plus certification for the second year running, closing material detection gaps identified during assessment.
- •Developed Sentinel KQL detection rules and workbooks aligned to ONR SyAPs and NIST CSF 2.0 control objectives.
Cyber Security Engineer
Feb 2022 – Nov 2024Sizewell C Nuclear
- •Secured Azure/M365 cloud architecture for a greenfield nuclear environment.
- •Delivered IAM, PIM and Conditional Access to strengthen access control posture.
- •Hardened endpoints via WDAC, Intune, Defender for Endpoint and application RBAC policies.
Cyber Security Consultant
Nov 2021 – Jan 2022FirstPort Property Management
- •Led end-to-end deployment of Microsoft Sentinel, including detection content and incident response automation.
- •Optimised the Microsoft 365 E5 security suite — Defender rollout, DLP and AIP labelling.
- •Architected Conditional Access and MCAS policies enforcing zero-trust access.
Security Consultant
Jun 2021 – Nov 2021TCS — Northern Power Grid
- •Led the endpoint cyber security programme for Northern Power Grid's OT pre-production environment.
- •Deployed Carbon Black EDR/Application control on-prem, with custom rule creation and tuning.
- •Authored HLD/LLD and CAB project documentation.
Lead Infrastructure Security Engineer
Jan 2020 – Jun 2021INEOS Oil and Gas
- •Led a NIST-aligned security programme across UK on-prem, cloud, IT and critical OT infrastructure.
- •Delivered Carbon Black EDR and Cisco Umbrella deployment with baseline policy and alert tuning.
- •Led IAM, Okta, O365 ATP and Fortinet firewall replacement projects.
Infrastructure Security Engineer
Oct 2017 – Nov 2019Kobalt Music
- •Deployed CIS Top 20 security controls and hardened server/desktop baselines globally.
- •Led global EDR, penetration testing and vulnerability management, including Carbon Black and Qualys.
- •Automated CIS-hardened Windows 10 builds, cutting build time by 66%.
Infrastructure Engineer
May 2017 – Sep 2017Kurt Geiger
- •Resolved service issues and closed ISO 27001 audit findings across HQ and DC sites.
- •Led decommissioning of legacy servers and migration to Server 2012 R2 with SQL upgrades.
- •Migrated business-critical IIS .NET web applications from Server 2000/2003 to 2012 R2.
Network Systems Analyst
Jan 2016 – Jan 2017ACCOR Hotels UK
- •Led ACCOR's PCI DSS/GDPR security rollout across UK hotels, contributing to successful certification.
- •Owned PCI DSS and Qualys vulnerability reporting, remediation and security controls delivery.
- •Coordinated MPLS-to-fibre migration to support secure network modernisation.
Network Systems Engineer
May 2015 – Dec 2015ACCOR Hotels UK
- •Delivered 3rd line support across 3 HQs, 250 sites, 2,700 users and 350 servers.
- •Supported server, network, corporate Wi-Fi and Oracle IPOS infrastructure.
- •Managed SCCM deployments and monthly patching to maintain security and system updates.
Infrastructure Engineer
Feb 2010 – Mar 2015Kent Wildlife Trust
- •Unified a fragmented four-site estate into a modernised, scalable architecture.
- •Delivered the organisation's foundational Disaster Recovery and Business Continuity posture.
Network Support Engineer
Jul 2006 – Dec 2009Stealth Solutions
Infrastructure Project Engineer
May 2005 – May 2006Connexions
Work
Case studies covering engagements across Azure security architecture, IAM, and cyber assurance are available on the case studies page. Articles on GRC, third-party risk and security-by-design are on the blog.