Director of Security

Our client is widely recognised as Europe’s most successful AI company of 2025. They reached a unicorn status after raising a $150m+ Series C, and 6 months later tripled their valuation to $3bn and raised a $250m+ Series D - all on the back of $60m 2025 ARR, double their target.

At the core of this growth is a bold technical vision: redefine how humans and machines interact in real time. Our client is building the real-time, voice-first infrastructure layer for AI, enabling low-latency, high-concurrency interactions between humans and intelligent systems at enterprise scale.

Role Overview:

Security isn't a support function here - it's the product. Our client's enterprise customers trust it with their most sensitive real-time conversations, so security is what wins deals and underpins the entire platform. As Director of Security, you will lead the product security function, owning both application and cloud security.

The foundations are there (ISO, SOC 2); this is a "10 to 100" role, not zero to one: as they scale into larger enterprise customers, security ownership gets centralised under you, with genuine ownership and executive visibility.

Key Responsibilities:

• Define and own the product security strategy end-to-end, across application security, cloud security, and detection and response
• Own application security across the SDLC - secure coding, threat modelling, and architectural reviews - without slowing engineering velocity
• Advance AI-specific security - securing LLM pipelines, prompt-injection surfaces, and sensitive data handling
• Partner closely with Engineering, Product, and Compliance to embed security into how the platform is built and shipped
• Lead, mentor and grow the team, and be the security voice in enterprise customer engagements

Qualifications:

• Proven track record leading security teams - including seniors and Principals - protecting large-scale, customer-facing products in a fast-moving environment.
• Deep understanding of application and cloud security, secure architecture, and enterprise-grade compliance requirements.
• Hands-on experience securing cloud-native, containerised environments (AWS/GCP, Kubernetes).
• Familiarity or strong interest in securing LLMs, agentic AI, or real-time intelligent systems.
• A pragmatic approach with the ability to translate risk into clear engineering priorities, plus excellent communication and stakeholder management skills.

If you're looking for the opportunity to shape security at one of world's most ambitious and well-funded AI companies - building a function that enables engineering, earns enterprise customer trust, and becomes a strategic advantage as the business scales – we'd love to hear from you.