The Company

We're partnering with an early-stage AI company building technology that helps organisations make better decisions from complex, fast-changing information.

At the heart of the business is a unique and growing data asset.

They're building an intelligence layer around this data — combining software engineering, data infrastructure, retrieval and AI to make it searchable, usable and trustworthy.

Data is the product. The frontend is the wrapper.

They already have customers and are now entering their next stage of growth, rebuilding the engineering team around a small number of exceptional hires.

This is a rare opportunity to join as one of the most senior technical people in the business and take significant ownership of the platform.

You'll be highly hands-on across Python, data, RAG, AI and infrastructure, while helping determine what gets built, how it's built and how the engineering function evolves.

You'll work directly with leadership, taking ambiguous problems and turning them into production software.

As the company scales, there is potential for this person to grow into broader technology leadership and ultimately a CTO-level role.

What You'll Be Doing

Own and evolve the core AI & data platform

Build backend services and APIs in Python

Build data pipelines and retrieval systems

Develop RAG and semantic search capabilities

Build production AI/LLM features

Make architecture and infrastructure decisions

Take ambiguous problems from 0→1

Help build and technically lead the engineering team





AI is deeply embedded into how the team builds. Engineers are encouraged to use AI coding tools extensively, while remaining responsible for understanding, testing and owning what they ship.

What They're Looking For

Excellent SQL / relational database knowledge

Experience with RAG, retrieval or semantic search

Experience owning production software end-to-end

Comfortable working across the full stack

Strong product and technical judgement

Comfortable solving highly ambiguous problems

Startup / scale-up experience

High ownership and autonomy

Technically strong while commercially minded

You don't need to already be a Tech Lead.

They're more interested in what you've owned, the decisions you've made and whether you're capable of becoming the person others rely on for technical judgement.

Interview Process

Initial conversation

60-minute technical discussion

Potential path from Lead Product Engineer → CTO

Become one of the most senior technical people in the business

Genuine ownership over product and architecture

Build across AI, RAG, data and backend engineering

Work directly with company leadership

Help build the engineering team around you

Existing customers with a major new product direction

Versátil London / remote working

Equity alongside salary

If you're a senior Product Engineer who wants more than another IC role — and wants the opportunity to build the product, shape the technology and potentially grow into leading the entire engineering function — we'd love to hear from you.

📌 Lead Product Engineer → CTO | Python, SQL, RAG, AWS, TypeScript | AI & Data Infrastructure, Start-up (Madrid)
🏢 Owen Thomas | B
📍 Madrid