Head of Security Operations in London

About Radiant

Radiant is redefining how AI infrastructure is built. We design and operate AI-native infrastructure platforms engineered for sovereignty, performance, and scale - powering GPU-native workloads, multi-tenant control planes, and high-performance AI systems for the most demanding environments. We are building purpose-built AI infrastructure from powered land, to compute, to software.

As we scale our operations and deploy capital into the next generation of AI infrastructure, we are looking to expand our security team with leaders who can combine technical strength with execution excellence and are driven to build.

Radiant was established by Brookfield, a leading global alternative asset manager with over US$1 trillion of assets under management across real estate, infrastructure, renewable power and transition, private equity and credit. Brookfield's global relationships, investment expertise and access to long-term institutional capital provide Radiant with a differentiated platform from which to develop, finance and operate AI infrastructure assets. This combination of entrepreneurial execution and institutional sponsorship enables Radiant to pursue large-scale GPU and AI infrastructure opportunities globally.

About the Role

• Location: London, UK
• Employment Type: Full-time, Permanent
• Reports to: Chief Customer Officer

We're looking for a Head of Security Operations to build Radiant's security function from the ground up. This is a founding role where you’ll help to define the strategy, tooling and operating model for security across our data centres, compute platform and network fabric.

You will also represent Radiant's security posture directly to customers and prospects who are evaluating us for their AI workloads. You will work closely with our Commercial, Compliance and Engineering teams, coordinating on shared risk reporting, security testing and audit evidence.

What You'll Do

• Security Strategy & Leadership: Build and own Radiant's security strategy from the ground up, including policy, standards and risk posture for customer-facing infrastructure. Develop our security practices, governance, risk and reporting. Define the roadmap and maturity targets for the function. Build the hiring plan and business case for the SecOps team as it scales.
• Customer-Facing Security & Trust: Contribute to Radiant's Trust Center as the primary resource for customers evaluating our security posture. Lead security input into customer due diligence, RFPs and technical evaluations, particularly for sovereign and regulated deployments. Represent Radiant directly with customers and prospects on security matters as part of the sales and onboarding process. Audit customer deployments for alignment to agreed security specs.
• Data Centre & Infrastructure Security: Source, deploy and operate security tooling for the Radiant DCs. Lead physical, environmental and infrastructure-layer security across Radiant's data centre sites. Manage site-level risk including access control, surveillance, third-party and vendor access, and environmental controls. Bring hands-on data centre security expertise; this is a core requirement for the role.
• Engineering Partnership: Define and own the tools strategy for the SecOps team. Collaborate with CTO and InfoSec teams to build/buy the necessary tooling. Build support across Engineering, Platform and Product for the security practice. Embed security into how Radiant designs and ships infrastructure without slowing delivery.
• Governance, Testing & Collaboration: Partner with the VP InfoSec on shared risk reporting, security testing (internal drills, external pentest) and audit evidence gathering. Develop security culture, development and training for the organisation. Maintain a clear division of ownership with the VP InfoSec, with regular collaboration expected across both domains.
• Incident Response & Resilience: Own incident response and crisis management when customer-facing infrastructure is affected. Run post-incident reviews and use them to drive resilience improvements. Communicate directly with customers during major incidents when required.

What You'll Bring

• Hands-on data centre security expertise, covering physical, environmental and infrastructure-layer security, gained in large-scale, high-availability environments.
• Experience building a security function or SOC from the ground up, without an inherited team or toolset.
• Experience representing security directly to customers and prospects, including at executive level.
• Strong stakeholder management skills across engineering leadership without relying on formal authority.
• Experience working alongside a peer GRC/Infosec function with clearly defined but collaborative boundaries.
• Experience owning incident response and resilience programmes at scale.

Nice to Have

• Experience securing AI-native, GPU-accelerated or HPC infrastructure specifically.
• Background in telecom, hyperscale cloud or colocation data centre operators.
• Familiarity with sovereign or regulated infrastructure security requirements.
• Experience with customer-facing security assurance processes such as RFPs, due diligence and trust centers.

Why Join Radiant?

• Build and own a new function at a rapidly scaling AI infrastructure business, with a genuine mandate to shape it.
• Work directly with Radiant's Customer Office leadership and C-suite, with real influence over how the company secures and sells its platform.
• Be part of a team whose work protects the infrastructure powering sovereign and enterprise AI deployments globally.
• Develop your career in a Brookfield backed company with resources, mentorship and genuine growth opportunities.