Lead Product Engineer → CTO | Python, SQL, RAG, AWS, TypeScript | AI & Data Infrastructure, Start-up | Technical Ownership, 0→1 | UK remote | Base £80-100K + Equity

Lead Product Engineer → CTO | Python, SQL, RAG, AWS, TypeScript | AI & Data Infrastructure, Start-up | Technical Ownership, 0→1 | UK remote | Base £80-100K + Equity
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.
The Role – Lead Product Engineer → CTO | Python, SQL, RAG, AWS, TypeScript | AI & Data Infrastructure, Start-up | Technical Ownership, 0→1 | UK remote | Base £80-100K + Equity
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
Design complex SQL/PostgreSQL data models
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
Establish engineering standards
Help build and technically lead the engineering team
Tech Stack - Lead Product Engineer → CTO | Python, SQL, RAG, AWS, TypeScript | AI & Data Infrastructure, Start-up | Technical Ownership, 0→1 | UK remote | Base £80-100K + Equity
Python | SQL | PostgreSQL | TypeScript | AWS | RAG | LLMs | APIs | Data Pipelines
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
Strong Python backend engineering
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
Short take-home — AI use encouraged
60-minute technical discussion
30-minute culture conversation
Why Join? - Lead Product Engineer → CTO | Python, SQL, RAG, AWS, TypeScript | AI & Data Infrastructure, Start-up | Technical Ownership, 0→1 | UK remote | Base £80-100K + Equity
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
Flexible 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.
Apply with your CV and we'll be in touch if there's alignment

Work arrangement
Yes