Senior Security Engineer in London

We help UK public sector organisations build and run digital services that are secure, trustworthy, and resilient. As a Senior Security Assurance Engineer in our Cyber practice, you'll take end-to-end ownership of security assurance work across complex government environments - designing audit approaches, leading risk assessments, and helping clients understand and improve their security posture in ways that are proportionate, practical, and grounded in how their services actually work. At Senior level, you're also expected to raise the standard of security practice around you - not just through your own work, but by mentoring colleagues, contributing to how the team operates, and helping clients build their own capability over time. We're a consultancy that believes good security outcomes come from embedding security into delivery as a continuous concern, not bolting it on at the end. You'll be central to making that real.

Key responsibilities

• Design and lead security audits across complex government systems - combining automated scanning with manual testing, producing findings that are clearly framed around risk and remediation rather than just compliance status.
• Drive continuous compliance monitoring against applicable standards and regulations - Cyber Essentials, the NCSC Cyber Assessment Framework, GovAssure, UK GDPR, and NIS Regulations - feeding posture data into governance and risk reporting rather than treating it as a point-in-time exercise.
• Lead risk assessments and threat-modelling sessions, selecting methodologies (ISO 27005, NIST RMF, STRIDE, MITRE ATT&CK) that are proportionate to system criticality, and ensuring findings feed into programme governance decisions rather than sitting in security documentation alone.
• Communicate security findings and risk clearly to a range of audiences - technical detail for engineering teams, risk-framed summaries for senior stakeholders - structuring reports around the decisions people need to make, not just the controls you've tested.
• Embed security as a continuous engineering concern, supporting threat modelling and security reviews throughout delivery, challenging designs that create unnecessary risk, and mentoring colleagues on secure-by-default practices.
• Support and assess supply-chain and third-party security, creating proportionate assurance processes aligned with recognised standards and helping clients identify and address gaps in how they manage vendor and software supply-chain risk.
• Mentor and coach colleagues and client team members, pairing on complex assurance work, sharing knowledge openly across the practice, and actively contributing to the capability of everyone around you - not just delivering your own work well.
• Contribute to the commercial and strategic health of engagements, staying alert to unmet client needs, managing scope within contracted boundaries, and surfacing opportunities or risks to account leadership as they arise.

Skills, knowledge and expertise

• Hold one of the following: Certified Information Systems Auditor (CISA), Systems Security Certified Practitioner (SSCP), or an equivalent audit and assurance practitioner credential.
• Certified in Risk and Information Systems Control (CRISC).
• Certified Information Systems Security Professional (CISSP).
• Experience advising clients on UK government security frameworks – including GovAssure, the NCSC Cyber Assessment Framework, Cyber Essentials Plus, and the HMG Security Policy Framework – and how they interact in practice.
• Experience leading risk assessments using structured methodologies (ISO 27005, NIST RMF, or FAIR) and embedding risk outputs into programme governance rather than treating them as standalone deliverables.
• Demonstrated ability to design security controls and governance approaches for cloud environments, with an understanding of how compliance requirements apply in AWS, Azure, or GCP contexts.
• Working knowledge of incident response planning, establishing policies, assessing team readiness, and mentoring others on preparedness, ideally in a government or regulated environment.
• Experience conducting or leading supply-chain security assessments, including third-party risk and software provenance, with reference to recognised standards.
• Familiarity with tools used for continuous compliance monitoring, automated controls testing, or cloud security posture management (for example, CSPM tooling, SIEM platforms, or vulnerability management tools).
• Evidence of actively shaping your own development, a T-shaped specialism, seeking and acting on feedback, and sharing learning openly with colleagues and the wider practice.
• Experience contributing reusable assets, playbooks, templates, tooling, or patterns back into a practice or community rather than leaving knowledge within a single engagement or team.
• Experience running or contributing to structured mentoring relationships, pairing sessions, or retrospectives in a way that measurably improved team capability or ways of working.
• Experience co-designing solutions with clients and stakeholders, bringing them into the process rather than presenting conclusions for approval, and delivering value anchored to outcomes rather than outputs.
• Experience conducting skills-based assessment of candidates, contributing to interview scripts, or calibrating assessment criteria to ensure fair and consistent evaluation.

What you'll bring

• Contextual judgement over formulaic approaches. You think carefully about what's proportionate for each engagement rather than reaching for the same framework every time. You can articulate trade-offs clearly and help clients understand the reasoning behind your recommendations.
• A team-first mindset. You take your own work seriously, and you take the growth of the people around you equally seriously. You pair, you share, you coach — and you make it safe for others to ask questions and admit gaps.
• Confidence communicating across boundaries. You're as comfortable presenting risk findings to a senior civil servant as you are working through a threat model with an engineering team. You adjust how you communicate without losing substance or clarity.
• Genuine ownership. You take responsibility for the outcomes of your work — maintaining momentum through ambiguity, escalating risks early rather than absorbing them, and seeing significant pieces of work through from start to finish.

Benefits

• 30 days Holiday – we offer 30 days of paid annual leave.
• Flexible Working Hours – we are flexible with what hours you work.
• Flexible Parental Leave – we offer flexible parental leave options.
• Remote Working – we offer part time remote working for all our staff.
• Paid counselling – we offer paid counselling as well as financial and legal advice.

Eligibility

An increasing number of our customers are specifying a minimum of SC check in order to work on their projects. As a result, we're looking for all successful candidates for this role to have eligibility. Eligibility for SC requires 5 years' UK residency and 5 years' employment history (or back to full-time education). Please note that if at any point during the interview process it is apparent that you may not be eligible for SC, we won't be able to progress your application and we will contact you to let you know why.

Equal Opportunity

We are collectively continuing to grow a culture that is happy, healthy, safe and inspiring for people of all backgrounds and experiences, so we encourage people from underrepresented groups to apply for roles with us.