Product Engineer

Atarus; Greater London; On-site; GBP 90,000 - 150,000; Full time

Job summary

Atarus, a well-funded AI startup, is hiring a Founding AI Product Engineer to join the founders in London. You will blend full-stack product engineering with sophisticated LLM systems to own complex workflows and production-grade AI features.

You will lead production LLM agents, multi-agent workflows, and human-in-the-loop review processes, while delivering data-heavy frontend products for professional users. A strong product instinct and full-stack versatility are essential.

Qualifications

• 4+ years of strong software engineering experience with production work on LLMs, agents and context engineering.
• Experience across full-stack product engineering and end-to-end feature delivery.

Responsibilities

• Own production LLM agents and multi-agent workflows.
• Implement human-in-the-loop systems to review and verify AI outputs.
• Develop data-heavy frontend products for complex professional workflows.
• Delivers features end-to-end—from customer problem to production.

Skills

LLM systems

Agent architectures

Context engineering

Full-stack development

Product instincts

Tools

Python

React

Job description

We’re working with a well-funded AI startup building an AI-native operating system for large-scale energy and infrastructure projects.

They’re hiring a Founding AI Product Engineer to work directly with the founders, combining full-stack product engineering with sophisticated LLM systems.

You’ll own

• Production LLM agents & multi-agent workflows
• Human-in-the-loop systems for reviewing and verifying AI outputs
• Data-heavy frontend products for complex professional workflows
• Features end-to-end — from ambiguous customer problem through to production

4+ years of strong software engineering experience, with genuine production experience across LLMs, agent architectures and context engineering. You’ll need to be comfortable across the full stack and have strong product instincts — this isn't a pure ML role.

The sweet spot

Founding-level ownership, meaningful equity, backing from leading VCs and AI investors, and the opportunity to build AI systems tackling a huge bottleneck in global energy infrastructure.