Founding Engineer

Delfa; Greater London; On-site; GBP 90,000 - 140,000; Full time

Benefits offered by this job

Private health insurance

Gym membership

Equity

25 days' holiday

Job summary

Delfa, a London-based startup building autonomous AI agents to fix clinical trials, is seeking a senior full-stack engineer to scale core systems.

You will own end-to-end architecture, design robust data pipelines, and deploy across trial sites, collaborating with a talented team in a fast-paced setting. This onsite role at our London office offers meaningful equity and opportunities to impact patient outcomes.

Qualifications

• 3+ years of professional full-stack engineering experience.
• Ability to own complex projects from architecture to deployment.
• Comfort with solving hard technical problems and refactoring when needed.

Responsibilities

• Design, build, and scale AI agent systems end-to-end across trial sites.
• Own complex projects from architecture to deployment with autonomy.
• Build and evolve infrastructure, observability, and monitoring at scale.
• Integrate cutting-edge models into production workflows and evaluate new capabilities.
• Design robust data pipelines for ingesting and serving healthcare data.

Skills

Full-stack engineering

Architecture & deployment

Ownership mindset

Tools

FastAPI

TypeScript

React

OpenAI/Anthropic

Temporal

PostgreSQL

Azure

Job description

About Delfa

Billions of people still suffer from every-day diseases.

One key reason? Clinical trials are broken.

Despite $120 billion spent each year, most trials are delayed due to bottlenecks like patient recruitment.

Delfa is fixing this with autonomous AI agents. We're building AI agents to automate clinical trials.

In the last year from we've already:

• Deployed onto 500+ trials across multiple conditions
• Reached seven figures in ARR, growing 25% MoM
• Raised an oversubscribed $3.8m seed from tier-one AI investors

What You'll Do

You'll build and scale the core systems that enable Delfa's AI agents to deliver real-world clinical impact.

• Design, build, and scale AI agent systems end-to-end: from voice interactions to intelligent workflow orchestration across trial sites
• Own complex projects from architecture to deployment, with real autonomy over technical decisions
• Build and evolve the infrastructure, observability, and monitoring systems needed to ensure quality and reliability at scale
• Integrate leading-edge models from AI labs into production workflows, evaluating and adopting new capabilities as the frontier moves
• Design robust data pipelines for ingesting, transforming, and serving high-quality healthcare data
• Continuously improve internal AI tooling and platform to unlock new use cases and increase team velocity

Our current tech stack

• FastAPI
• Pydantic
• TypeScript
• React
• OpenAI / Anthropic
• Temporal
• PostgreSQL
• Honeycomb
• PlanetScale
• Azure

You’ll Be A Great Fit If…

• You have 3+ years of professional full-stack engineering experience: We're looking for somebody comfortable with solving hard technical problems, refactoring when needed, and knowing what's enough and what's too much to solve a problem.
• A track record of building high-quality products fast: Delfa's got big ambitions to materially accelerate getting life saving treatments to market. This is necessary and urgent work so we need individuals who can deliver.
• An ownership mindset: We position our team to understand customer problems, give you the autonomy to find the best path forward, and expect you to own the solutions.
• A growth mindset: We're looking for people who take pride in their work and are always looking to improve it. If your work doesn't matter to you, it won't end up mattering to our customers. If you're not growing, your impact won't grow either.

Life at Delfa

Delfa is building a generational company to transform the way medications reach millions of patients in need.

This is your opportunity to get in on the ground floor and work alongside the highest talent density team in the space, onsite at our London office 5 days a week:

• A wine-snob who built foundation models at Roche during ETH Zurich PhD
• A former hedge fund trader with world class causal AI knowledge
• A medical doctor turned AI engineer who builds prototypes on the weekend for fun
• A ginger bloke who deployed production AI for J&J, Medtronic, and Exscientia

What we offer

• Competitive salary + meaningful equity
• Private health insurance and gym membership
• 25 days' holiday + UK public holidays
• Modern office space 5 mins from Old Street station
• True 0 → 1 ownership. You'll take full responsibility for critical product features that get new treatments to patients, faster.

Our Hiring Process

• Intro chat with Gustav (CTO) - 30 mins: An informal discussion about your experiences, values, and career goals, and give you an opportunity to get a sense of the role and the team. After this call we may ask you to share some work you're proud of.
• Coding Challenge - 90 mins: No artificial interview questions. Instead, you will work through a real-world challenge similar to problems we solve every day. You are welcome to use AI tools. We believe great engineers should know how to solve problems effectively, including with AI.
• System Design Challenge - 90 mins: We'll invite you to our office to spend time with us in person. Together, we will work through a real-world system design problem. This is the best opportunity for you to see what it would be like to work with us, and for us to understand how you think and collaborate.
• Offer. If all the above goes well then you'll receive an offer from us!

If helping unstick clinical trials and getting life-saving treatments to patients faster sounds like your idea of important work, let's talk.