AI Product Engineer (up to £200k)

Dex; Greater London; On-site; GBP 70,000 - 110,000; Full time

Job summary

Dex is partnering with a startup building the first AI-native certification body to independently assess AI systems for security and reliability. The Product Engineer will own end-to-end development across the front end, back end, and AI-agent infrastructure.

You will design and implement full-stack features, build the core agent infrastructure, and define safeguards like sandboxing and containment. Join a founding team shaping how AI systems are audited.

Qualifications

• Shipped real systems with substantive decisions on agent harnesses, evals, sandboxing, or multi-component system/tool design.
• Proven ability to ship across the interface, backend, data, and deployment layers.
• Evidence of exceptional output: open-source contributions, personal projects, research, or hackathon results.

Responsibilities

• Design and implement full-stack product features, from user interface to backend services.
• Build the core AI agent infrastructure and evaluation frameworks for system certification.
• Define and implement critical safeguards for AI systems, including agent sandboxing and hallucination containment.
• Drive product development from initial concept through to production deployment, ensuring direct impact on audit outcomes.
• Contribute to the technical architecture and foundational engineering practices of a nascent team.

Skills

Shipped real systems

Full-stack delivery

First-principles thinking

Evidence of output

Job description

This role is with one of Dex's trusted partner companies. We work closely with their teams to truly understand their culture, goals, and what they're looking for, so we can match you with the right opportunity and give you context about the role before you commit to a process.

The role

This company is building the first AI-native certification body, independently assessing whether AI systems are secure, reliable, and behaving as intended. Founded by engineers who spent years deploying enterprise AI across regulated industries, they are backed by leading investors and and already have paying enterprise customers.

You'll join a genuinely small, founding team as a Product Engineer, owning products end-to-end across the front end, back end, and the AI-agent infrastructure. This isn't building on top of an existing process; it's building the process itself: the harnesses, evals, and safeguards that decide whether an AI system's behavior can be certified. Your decisions on agent sandboxing, hallucination containment, and tool design will define how AI systems are audited.

The work

• Design and implement full-stack product features, from user interface to backend services.
• Build the core AI agent infrastructure and evaluation frameworks for system certification.
• Define and implement critical safeguards for AI systems, including agent sandboxing and hallucination containment.
• Drive product development from initial concept through to production deployment, ensuring direct impact on audit outcomes.
• Contribute to the technical architecture and foundational engineering practices of a nascent team.

What You Bring

• Shipped real systems where you made substantive decisions on agent harnesses, evals, hallucination containment, sandboxing, or multi-component system/tool design.
• Proven ability to ship across the interface, backend, data, and deployment layers.
• Reasons from first principles, choosing tools deliberately rather than following a playbook.
• Evidence of exceptional output: professional work, open-source contributions, personal products, research, or hackathon results. Roughly 2+ years in a role is useful, but the evidence matters more than the tenure.