Cyber Security Architect & Engineering Lead

Circle Recruitment; Greater London; Hybrid; GBP 70,000 - 80,000; Full time

Job summary

Circle Recruitment seeks a senior Cyber Security Architect & Engineering Lead in London, hybrid, to strengthen security architecture and hands-on engineering capability. You will own security architecture, engineering, operations and improvements, mentoring others and delivering secure controls.

The role emphasizes leadership, technical ownership, and influencing stakeholders to implement pragmatic security improvements across Microsoft 365, Azure and related tooling.

Qualifications

• Hands-on security engineering and architecture in a Microsoft-centric environment.
• Strong experience with Microsoft Sentinel: setup, configuration, tuning, detection and SecOps.
• Deep knowledge of Microsoft Defender, Entra ID, Azure, Microsoft 365 and related tooling.
• Experience with identity, Zero Trust, cloud, data, endpoint, network, application and API security; secure software development.
• Experience with security architecture reviews, threat modelling, control design and reference architectures.
• Strong ISO 27001 experience including controls, audits, remediation and continual improvement.
• Experience in incident response, detection engineering, threat hunting, vulnerability management and security automation.
• Ability to own initiatives from problem identification to business case, implementation and measurement.

Responsibilities

• Define and evolve security architecture across identity, endpoints, networks, cloud, SaaS, data, applications and integrations.
• Design, implement and improve security controls with emphasis on Zero Trust, secure-by-design and automation.
• Lead security architecture reviews and threat modelling for major projects and high-risk integrations.
• Own security initiatives from problem identification through to implementation and validation.
• Provide technical leadership across Microsoft Sentinel, Defender and wider SecOps, including configuration and monitoring.
• Provide oversight across incident response, threat hunting, vulnerability management and security recovery.
• Support complex incident response with internal teams, SOC providers and partners.
• Improve vulnerability management using business risk, exploitability and threat intelligence.
• Lead and support ISO 27001 controls, audits and continual improvement.
• Support Cyber Essentials Plus, client assurance and regulatory security requirements.
• Lead on AI security, including AI governance and practical controls for AI technologies.
• Identify opportunities to automate security and assurance processes.

Skills

Security engineering

Security architecture

Microsoft Sentinel

Microsoft Defender

Entra ID

Azure

Threat modelling

ISO 27001

Automation

Leadership

Mentoring

Python

PowerShell

Logic Apps

Azure Functions

APIs

Tools

Python

PowerShell

Logic Apps

Azure Functions

APIs

Job description

Cyber Security Architect & Engineering Lead

Location: London, hybrid
Salary: £70,000 - £80,000

Our client is seeking a senior, hands-on Cyber Security Architect & Engineering Lead to strengthen its security architecture and engineering capability.

Reporting to the Head of Information Security, this is a senior technical leadership role and genuine second in command, providing independent ownership across security architecture, engineering, operations and technical improvement.

You will combine strong technical expertise with the ability to influence stakeholders, build business cases, deliver initiatives and mentor others. This is not a purely advisory, SOC or GRC role, the successful candidate will be expected to design, implement, improve and validate security controls.

Key Responsibilities

• Define and evolve security architecture across identity, endpoints, networks, cloud, SaaS, data, applications and integrations.
• Design, implement and improve security controls, with a focus on Zero Trust, secure-by-design and automation.
• Lead security architecture reviews and threat modelling for major projects, technologies and high-risk integrations.
• Own security initiatives from problem identification and business case through to implementation and validation.
• Provide technical leadership across Microsoft Sentinel, Defender and wider SecOps, including configuration, tuning, detection engineering and monitoring.
• Provide oversight across incident response, threat hunting, vulnerability/exposure management and security recovery.
• Support complex and high-severity incident response with internal teams, SOC providers and specialist partners.
• Improve vulnerability management using business risk, exploitability, attack-path context and threat intelligence.
• Lead and support practical implementation of ISO 27001 controls, audits, remediation and continual improvement.
• Support Cyber Essentials Plus, client assurance and regulatory/contractual security requirements.
• Lead on AI security, including practical controls for Microsoft 365 Copilot, AI agents, custom AI applications and emerging technologies.
• Identify opportunities to automate security and assurance processes.

What We're Looking For

• Hands-on security engineering and architecture experience within a Microsoft-centric environment.
• Strong Microsoft Sentinel experience, including setup, configuration, tuning, detection and SecOps.
• Strong knowledge of Microsoft Defender, Entra ID, Azure, Microsoft 365 and related security tooling.
• Identity, Zero Trust, cloud, data, endpoint, network, application and API security, plus secure software development.
• Experience with security architecture reviews, threat modelling, control design, technical standards and reference architectures.
• Strong practical ISO 27001 experience, including controls, audits, remediation and continual improvement.
• Experience across incident response, detection engineering, threat hunting, vulnerability/exposure management and security automation.
• Proven ability to own initiatives from identifying a problem and building the business case through to implementation and measuring improvement.
• Automation skills using Python, PowerShell, Logic Apps, Azure Functions, APIs, infrastructure as code or equivalent.
• Ability to influence senior stakeholders, communicate technical risk clearly and drive change without relying solely on formal authority.
• Mentoring colleagues and providing technical leadership.Experience in a regulated, client-confidential or professional services environment is advantageous.
• AI security, AI governance or security automation experience is highly desirable.

Desirable

• Microsoft Certified: Cybersecurity Architect Expert / SC-100
• CISSP or CCSP
• Microsoft security certifications such as AZ-500 or SC-200
• GIAC certifications covering incident response, cloud, detection or forensics
• ISO 27001 Lead Implementer or Lead Auditor
• SABSA, TOGAF or equivalent

About You

You will be a hands-on security professional and technical leader comfortable moving between architecture, engineering, configuration, testing and stakeholder engagement.

You take ownership rather than simply identifying problems. You will be able to demonstrate examples of identifying a security gap or opportunity, building the case for change, gaining approval and delivering successful implementation.

Our client is not seeking a predominantly SOC alert-triage or heavily GRC focused candidate without strong technical experience. Equally, strong engineering ability alone is not enough; you will need leadership, ownership, commercial awareness and the ability to influence the wider business.

Cyber Security Architect, Engineering Lead, Cyber Security, Microsoft Sentinel, Defender, Azure, Microsoft 365, Entra ID, SecOps, ISO 27001, CISSP, CCSP, TOGAF, SABSA