Security Architecture Lead - AI Infrastructure

AI Startups UK; Greater London; Hybrid; GBP 120,000 - 180,000; Full time

Benefits offered by this job

Competitive salary

Equity & ownership

Private healthcare

Visa sponsorship & relocation

London office - on site

Job summary

Callosum, London-based AI infrastructure company, seeks a security leader to design and guarantee security across APIs, orchestration, agentic systems, and physical infrastructure. You will translate requirements for engineering teams, drive assurance for deployments, and build a dedicated security function.

You will own security strategy, oversee threat modelling and incident response, and lead a team across architecture and operations, partnering with customers and partners in high-stakes

Qualifications

• Experience owning security assurance or sensitive deployments end-to-end.
• Strong foundations in infrastructure or security engineering to challenge architecture decisions.
• Experience securing on-premise, air-gapped, multi-tenant or high-assurance environments.
• Proven ability to build and lead security teams with sound risk judgment.

Responsibilities

• Define security architecture and requirements across APIs, orchestration, and infrastructure.
• Translate security requirements into engineering work with measurable guarantees.
• Lead security assurance for deployments from requirements through approval.
• Build and lead the security team across architecture, threat modelling, incident response, and operations.

Skills

Security architecture

Infrastructure security

Security team leadership

Risk assessment

Job description

Callosum, London-based AI infrastructure company, seeks a security leader to design and guarantee security across APIs, orchestration, agentic systems, and physical infrastructure. You will translate requirements for engineering teams, drive assurance for deployments, and build a dedicated security function.

You will own security strategy, oversee threat modelling and incident response, and lead a team across architecture and operations, partnering with customers and partners in high-stakes