Principal Security Architect

We are seeking an experienced and commercially minded Principal Security Architect to join an established a rapidly growing IT Service Provider. This is a senior client-facing role responsible for leading the design, assurance and delivery of complex security solutions across enterprise and public sector customers.

The successful candidate will act as a trusted advisor to C-level stakeholders, security leaders, and technical teams, helping clients develop and implement security strategies, architectures and operational capabilities that reduce risk and support business objectives.

A key focus of the role will be security monitoring and detection capabilities, with demonstrable expertise in Microsoft Sentinel, SIEM/SOAR design, security operations transformation and cloud-native security architectures.

Working closely with sales, delivery and technical teams, you will provide thought leadership, contribute to solution development, support pre-sales engagements and lead security architecture initiatives across a diverse customer base.

Key Responsibilities
Client Advisory & Leadership

• Act as the lead Security Architect across assigned Managed Services clients.
• Act as a trusted security advisor to client stakeholders, including CIOs, CISOs and security leadership teams.
• Lead security architecture engagements from discovery through design and implementation.
• Define security strategies, roadmaps, target architectures, and governance standards.
• Produce and assure HLDs, LLDs, and reference architectures aligned to Zero Trust and Secure by Design principles.
• Lead architecture for Microsoft Entra ID, Active Directory, Identity Governance, PIM, Conditional Access, SSO, Federation, and B2B/B2C identity.
• Provide architectural ownership across the Microsoft security stack, including Defender, Sentinel, Purview, Intune, Security Copilot, Azure Security, and Microsoft 365 Security & Compliance.
• Translate business requirements into secure, scalable and practical security solutions.
• Present architectural recommendations and security strategies to executive audiences.
• Lead security workshops, assessments and roadmap development activities.

Security Architecture

• Define and maintain enterprise security architectures aligned with business objectives.
• Design security controls across cloud, hybrid and on-premise environments.
• Develop security reference architectures, standards and patterns.
• Ensure solutions align with recognised frameworks including:
  • NCSC Cyber Assessment Framework
  • NIST Cyber Security Framework
  • ISO 27001
  • CIS Controls
  • Zero Trust principles

Microsoft Security & Sentinel

• Lead the architecture, deployment and optimisation of Microsoft Sentinel environments.
• Design SIEM and SOAR solutions to enhance threat detection, incident response and operational efficiency.
• Create and optimise analytics rules, detection use cases, automation playbooks and dashboards.
• Drive security monitoring maturity programmes and SOC transformation initiatives.
• Integrate Sentinel with Microsoft Defender technologies and third-party security platforms.
• Advise clients on security operations processes, reporting and threat management.

Cloud Security

• Design secure cloud-native architectures across Microsoft Azure environments.
• Support cloud migration and transformation programmes.
• Define security controls covering:
  • Identity and Access Management
  • Privileged Access
  • Data Protection
  • Network Security
  • Security Monitoring
  • Threat Detection and Response

Pre-Sales & Business Development

• Support sales and account teams in developing cyber security opportunities.
• Lead technical discussions during bids, tenders and client presentations.
• Contribute to proposals, statements of work and solution documentation.
• Assist with service innovation and development of new cyber security offerings.
• Represent the organisation at client events, conferences and industry forums.

Governance & Assurance

• Perform architecture reviews and security assurance activities.
• Assess risk and provide pragmatic remediation recommendations.
• Produce high-quality architecture documentation and design artefacts.
• Provide technical leadership and mentoring to architects, consultants and engineers.

Essential Skills & Experience
Security Architecture

• Proven experience operating as a Lead, Principal or Enterprise Security Architect.
• Strong understanding of enterprise security architecture methodologies.
• Experience designing security solutions within large and complex organisations.
• Deep knowledge of security frameworks and regulatory requirements.

Microsoft Security Expertise

• Extensive experience with:
  • Microsoft Sentinel
  • Microsoft Defender XDR
  • Microsoft Defender for Cloud
  • Microsoft Entra ID
  • Azure Security Services
  • Microsoft Purview

Security Operations

• Strong understanding of:
  • SIEM
  • SOAR
  • SOC Operations
  • Threat Detection Engineering
  • Incident Response
  • Threat Intelligence
  • Security Monitoring

Cloud & Infrastructure

• Strong Azure security architecture experience.
• Knowledge of hybrid cloud environments.
• Experience securing:
  • Identity platforms
  • Networks
  • Endpoints
  • Applications
  • Data services

Consulting & Stakeholder Management

• Excellent client-facing and communication skills.
• Ability to engage effectively at Board, Executive and Technical levels.
• Strong workshop facilitation and presentation skills.
• Commercial awareness and experience supporting sales engagements.

Desirable Experience

• Managed Security Services (MSSP) environments.
• Security Operations Centre transformation programmes.
• DevSecOps and secure software development practices.
• OT/ICS security experience.
• Public sector, financial services or regulated industry experience.
• Experience working within a UK IT Services, Consulting or Systems Integrator organisation.

Certifications
Highly desirable certifications include:

• Microsoft Certified: Cybersecurity Architect Expert (SC-100)
• Microsoft Security Operations Analyst (SC-200)
• CISSP
• CCSP
• SABSA
• TOGAF
• Azure Solutions Architect Expert
• Certified Cloud Security Professional (CCSP)
• GIAC Security Certifications