Founding AI Product Engineer

Calibre Technologies Inc.; Greater London; Hybrid; GBP 70,000 - 110,000; Full time

Job summary

Calibre Technologies Inc. in London is seeking a Product Engineer to join the founding team and build AI-native certification products, spanning front-end, back-end, and agent infrastructure.

You’ll work from discovery through production, designing systems with a language-agnostic, first-principles approach and a focus on reliable, measurable quality. Collaboration and pragmatic tool choices are valued as outcomes scale.

Qualifications

• Demonstrable AI engineering depth with real systems showing decisions about agent harnesses, evals, hallucination containment, performance, agent sandboxing or MCP/tool design.
• Strong product engineering and technical judgment; ships across interface, backend, data and deployment, reasoned with first principles.
• Product instinct and clear collaboration; asks questions, tests quickly, communicates clearly and cares about outcomes.
• Evidence of shipped work through professional work, open-source contributions, personal projects or hackathon results; ~2+ years useful but evidence matters more.

Responsibilities

• Own products across the whole stack. Build and ship across front-end, back-end and AI-agent infrastructure.
• Build products end-to-end. Design systems from discovery through to production.
• Engineer reliable agent systems. Design harnesses, evals and safeguards that keep quality measurable.

Job description

Calibre Technologies Inc. in London is seeking a Product Engineer to join the founding team and build AI-native certification products, spanning front-end, back-end, and agent infrastructure.

You’ll work from discovery through production, designing systems with a language-agnostic, first-principles approach and a focus on reliable, measurable quality. Collaboration and pragmatic tool choices are valued as outcomes scale.