Founding Engineer — Build AI-Driven Backend & Platform

Dex; Greater London; On-site; GBP 110,000 - 170,000; Full time

Job summary

Dex, in collaboration with its partner company, is hiring a Founding Engineer to own end‑to‑end backend architecture and AI workflow design. You will lead Python backend work with FastAPI, shape the PostgreSQL data layer, and contribute to a React frontend as needed, while driving CI/CD and Azure deployments.

Occasional travel to the Cambridge office is expected. You will work in a small, high‑calibre team alongside leadership to ship robust, scalable solutions that integrate AI and

Qualifications

• Owns an area from requirements to production in a startup context.
• Strong Python backend expertise with attention to design patterns.
• Experience building with large language models in real systems.
• Uses AI coding tools as a regular part of workflow.
• Willing to travel weekly to the Cambridge office.

Responsibilities

• Build agentic AI workflows that perform in production.
• Lead backend development in Python and FastAPI.
• Architect the PostgreSQL data layer.
• Drive CI/CD and Azure deployments.
• Contribute to the React frontend when needed.

Skills

Python backend

Domain‑driven design

Clean architecture

Event‑driven patterns

LLM production experience

AI coding tools

Tools

PostgreSQL

FastAPI

React

Azure

CI/CD

Job description

Dex, in collaboration with its partner company, is hiring a Founding Engineer to own end‑to‑end backend architecture and AI workflow design. You will lead Python backend work with FastAPI, shape the PostgreSQL data layer, and contribute to a React frontend as needed, while driving CI/CD and Azure deployments.

Occasional travel to the Cambridge office is expected. You will work in a small, high‑calibre team alongside leadership to ship robust, scalable solutions that integrate AI and