Founding Engineer at Delfa

Jack & Jill; Greater London; On-site; GBP 90,000 - 150,000; Full time

Job summary

Jack & Jill seeks a Founding Engineer to build and scale core AI agent systems powering autonomous workflows in clinical trial tech. You will own complex projects from architecture to deployment, including voice interaction infrastructure, in a fast-paced, high-autonomy environment.

Join a high-talent team in London, shaping products with significant patient impact while partnering with researchers and engineers to push healthcare AI forward.

Qualifications

• 2+ years of full-stack engineering experience
• Ownership mindset with track record of delivering high-velocity products
• Strong technical foundation in modern stacks and systems design

Responsibilities

• Architect and scale core systems for AI agents and voice workflows
• Own features end-to-end from design to deployment
• Collaborate onsite in London with multidisciplinary team

Skills

Full-stack engineering

Ownership mindset

Architectural thinking

FastAPI

TypeScript

React

PostgreSQL

Temporal

Tools

FastAPI

TypeScript

React

PostgreSQL

Temporal

Job description

Job Title

Founding Engineer

Salary

Not Disclosed

Company Description

$3.8M Seed-funded AI startup backed by Air Street Capital automating clinical trial recruitment

Job Description

You will build and scale the core systems powering autonomous AI agents that accelerate life-saving medical treatments. Working in a high-talent density team, you will own complex technical projects from architecture to deployment, orchestrating intelligent workflows across trial sites and handling voice interactions to solve the multi-billion dollar clinical trial bottleneck.

Location

London, UK

Why this role is remarkable

• Join an elite technical team including foundation model researchers, world-class causal AI experts, and engineers from top-tier biotech firms like Exscientia.
• Extraordinary traction with seven-figure ARR, 25% month-on-month growth, and deployment across 300+ clinical trials in less than one year.
• High-autonomy 0-1 environment where your engineering decisions directly impact how quickly patients receive life-saving treatments for everyday diseases.

What You Will Do

• Architect and scale core systems for AI agents, including intelligent workflow orchestration and real-time voice interaction infrastructure.
• Take full end-to-end ownership of critical product features, from initial design and system architecture to production deployment.
• Collaborate onsite in London with a multidisciplinary team of MDs and AI researchers to solve complex engineering challenges in the healthcare space.

The ideal candidate

• 2+ years of full-stack engineering experience with a track record of building high-quality products at high velocity.
• Strong builder instincts and an ownership mindset, demonstrated through professional work, side projects, or open-source contributions.
• Proficiency in modern tech stacks, ideally including FastAPI, TypeScript, React, PostgreSQL, and experience with workflow engines like Temporal.