Security control assurance specialist in London

Colt provides network, voice and data centre services to thousands of businesses around the world, allowing them to focus on delivering their business goals instead of the underlying infrastructure.

We are seeking a detail-oriented and proactive security control assurance specialist to ensure the design, implementation, and ongoing effectiveness of security controls across the organization. This role is critical in validating that security controls meet regulatory, legal, and organizational requirements and are operating effectively to mitigate risk.

The ideal candidate has strong experience in control testing, audits, and compliance frameworks (e.g., ISO 27001, NIST, SOC 2, NIS2), combined with analytical thinking and stakeholder engagement skills.

What you will do:

• Control Assurance & Testing
  • Plan and execute control assurance activities, including testing and validation of security controls.
  • Develop and maintain control testing methodologies, scripts, and procedures.
  • Perform periodic and continuous control monitoring to ensure ongoing effectiveness.
  • Identify control gaps, deficiencies, and areas for improvement.
• Compliance & Risk Alignment
  • Assess controls against relevant frameworks (e.g., ISO 27001, NIST CSF, CIS Controls, SOC 2, NIS2).
  • Assess control effectiveness across: Design Effectiveness (DE), Operating Effectiveness (OE) and Control Automation (CA).
  • Support regulatory and internal compliance initiatives.
  • Ensure controls align with organizational risk appetite and policies.
• Audit Support
  • Act as a key point of contact for internal and external audits.
  • Provide evidence, documentation, and walkthroughs for auditors.
  • Track audit findings and support remediation efforts.
• Reporting & Documentation
  • Document control testing results, findings, and risk implications.
  • Produce clear and concise assurance reports for management and stakeholders.
  • Maintain control inventories and assurance documentation.
• Stakeholder Collaboration
  • Partner with IT, security engineering, and business teams to evaluate controls.
  • Support control owners in remediation planning and execution.
  • Provide guidance on control design and best practices.

Must haves:

• 3–6+ years of experience in information security, IT audit, or GRC.
• Proven experience with security control testing and assurance activities.
• Strong knowledge of one or more frameworks: ISO 27001 / ISO 27002, NIST CSF / NIST 800-53, SOC 2 / ISAE 3402, CIS Critical Security Controls.
• Strong analytical and problem-solving skills.
• Attention to detail and high level of accuracy.
• Ability to interpret technical controls and translate into business risk.
• Excellent communication and stakeholder management skills.
• Ability to manage multiple priorities and deadlines.

Might haves:

• Professional certifications such as: CISA, CISM, CISSP, CRISC or equivalent.
• Experience with regulatory requirements (e.g., NIS2, GDPR, SOX).
• Familiarity with GRC tools (e.g., ServiceNow GRC, Archer, OneTrust).
• Experience with cloud environments (Azure, AWS, GCP) and related controls.

What we offer you:

At Colt, you’ll make a difference. Because around here, we empower people. We don’t tell you what to do. Instead, we employ people we trust, who come together across the globe to create intelligent solutions. Our global teams are full of ambitious, driven people, all working together towards one shared purpose: to put the power of the digital universe in the hands of our customers wherever, whenever and however they want. We give our people the opportunity to inspire and lead teams, and work on projects that connect people, cities, businesses, and ideas. We want you to help us change the world, for the better.

Diversity and inclusion: Inclusion and valuing diversity of thought and experience are at the heart of our culture here at Colt. From day one, you’ll be encouraged to be yourself because we believe that’s what helps our people to thrive. We welcome people with diverse backgrounds and experiences, regardless of their gender identity or expression, sexual orientation, race, religion, disability, neurodiversity, age, marital status, pregnancy status, or place of birth.

Most recently we have:

• Signed the UN Women Empowerment Principles which guide our Gender Action Plan.
• Trained 60 (and growing) Colties to be Mental Health First Aiders.

Please speak with a member of our recruitment team if you require adjustments to our recruitment process to support you. For more information about our Inclusion and Diversity agenda, visit our DEI pages.

Benefits: Our benefits support you through all parts of life, for both physical and mental health.

• Flexible working hours and the option to work from home.
• Extensive induction program with experienced mentors and buddies.
• Opportunities for further development and educational opportunities.
• Global Family Leave Policy.
• Employee Assistance Program.
• Internal inclusion & diversity employee networks.

When you join Colt you become part of our global network. We are proud of our colleagues and the stories and experience they bring – take a look at ‘Our People’ site including our Empowered Women in Tech.