Lead Security Architect

Join the Home Office as a Lead Security Architect and steer the secure‑by‑design delivery of critical systems that protect citizens and national interests. Working with the Principal Security Architect, you will own security architecture for a major portfolio, translate business goals and threat intelligence into practical controls, and mentor SEO‑level architects to raise capability across multiple programmes.

You will engage senior stakeholders, balance risk against usability and cost, and shape patterns that let teams adopt cloud, DevSecOps, IoT and zero‑trust approaches safely. If you can blend deep technical insight with clear, influential communication and enjoy turning complex risks into elegant proportionate solutions, this role offers the chance to make a tangible impact on services millions rely on every day.

As Lead Security Architect you will direct secure architecture across a portfolio worth hundreds of millions of pounds. Working with product owners, delivery managers and enterprise architects, you will ensure every new or changed service conforms to Home Office and NCSC standards while enabling rapid, user‑centred delivery.

You will analyse emerging threats, advise on proportional mitigations, and produce or tailor reference patterns covering identity, network segmentation, container security, data protection, and monitoring. By modelling risks with frameworks such as ISO 27005, NIST, or STRIDE, you will justify design choices to technical and non‑technical audiences and document them for re‑use.

What You'll Do:

• Set portfolio‑level vision & patterns in line with Principal Security Architect strategy, translating them into reusable templates and guardrails.
• Lead architecture reviews for high‑risk projects, providing actionable recommendations and tracking remediation through to closure.
• Perform and interpret threat‑modelling / pen‑test results, converting findings into road‑mapped improvements and measurable risk reductions.
• Advise on security controls for hybrid and cloud platforms (AWS, Azure, Kubernetes, serverless), balancing usability, cost and compliance.
• Mentor and quality‑assure SEO Security Architects' work, fostering a culture of continuous learning and knowledge sharing.
• Engage senior stakeholders across technology, policy and operations, presenting security trade‑offs in business terms and gaining consensus.
• Scan the horizon for emerging threats, tooling and regulatory change, recommending timely adoption or mitigation strategies.
• Oversee vendor and SaaS evaluations, ensuring contracts include appropriate security clauses and ongoing assurance.

Essential skills:

• Secure‑system design leadership: demonstrable track record creating or validating architectures for large‑scale, high‑risk services using recognised frameworks (SABSA, TOGAF, NCSC).
• Risk‑based decision‑making: expert in ISO 27001 / NIST / CIS controls, able to quantify and articulate risk, then select proportionate, cost‑effective controls.
• Technical depth: hands‑on knowledge of cloud security, IAM, container & API security, network segmentation, encryption and DevSecOps toolchains; capable of explaining exploitability of complex vulnerabilities.
• Pen‑testing & threat‑modelling: scoping, overseeing and translating results into enforceable patterns and backlog items.
• Influential communication: proven ability to engage C‑suite and delivery squads alike, adapting style to gain agreement and drive secure‑by‑design culture.
• Mentoring & governance: experience line‑managing or coaching security architects/engineers and running architecture assurance or design‑review boards.

Why join us:

At the Home Office, your work has real-world impact, shaping the safety and security of millions. We offer:

• Meaningful Work: Contribute to critical national security and public service initiatives.
• Career Growth: Benefit from tailored development frameworks and professional communities.
• Flexible Working: Balance your professional and personal life with hybrid work options.
• Diversity and Inclusion: Join a workplace where your unique background and talents are celebrated.
• Learn more about our benefits: Benefits - Home Office Careers

Additional Information:

• This role requires SC clearance. To meet national security vetting requirements, you must typically have been resident in the UK for at least five years. Unfortunately, we cannot sponsor visas.