Product Engineer (all levels)

I quit medicine because I kept watching patients die needlessly, for avoidable reasons. In almost every case, the medical knowledge and clinicians were there. It was the system that failed: the way information moved, decisions got routed, and fragmented teams and data turned solvable problems into tragedy.

I started the company to change that.

Our mission is human wellbeing, and we believe personalised medicine will transform it. Our founding insight is that getting there requires a system that learns continuously from care and its outcomes, optimising for human wellbeing. Building that learning engine is the opportunity at the heart of the company.

We're now in 1,000+ clinics across 4 product lines, serving more than 25% of the UK population. We are cash flow positive, growing fast, and have a tight crew of ~45 people who care deeply for each other and the mission. Everyone has real ownership and a voice in decisions.

Multiple trillion-dollar companies will be built in healthcare over the next two decades. We intend to be one of them.

If you want to work on problems where the stakes are high, you belong at the company. Your work here will save lives.

-Shun

Long before the "vertical AI" craze, we were obsessed with active reinforcement learning—a niche field in 2021 that the world, pre-ChatGPT, largely ignored.

Our trajectory has been unwavering since our YC application: achieving the "holy grail" of personalized medicine and deep phenotyping. This is powered by our proprietary active learning architecture - a system we codified in a 2021 patent that anticipated the Sparse Mixture of Experts (MoE) and active learning loops now foundational to modern LLMs.

While others are just arriving at the party, we’ve spent years executing a plan to build what is now one of the world’s largest, highest-quality labeled datasets.

We’re looking for someone who

• Has a track record of relentless shipping.

• Has proven ability to navigate ambiguity and tackle novel technical challenges from conception to production.

• Has strong CS Fundamentals. A deep understanding of data structures, algorithms (e.g., breadth-first search), and first-principles thinking to solve complex product problems.

• Is expert-level in TypeScript (TS). Proficiency in building type-safe, scalable applications. You are a full-stack expert in the JavaScript/Node.js ecosystem with a pragmatic approach to tech debt and tool selection.

• Has hands-on expertise with React, Angular, or Node.js, with the ability to move between frontend and backend as needed.

• Has experience architecting on AWS (specifically Lambda, DynamoDB, SQS, and CloudFormation) or a proven "hungry to learn" mindset regarding serverless infrastructure.

• Is disciplined towards best practice version control, CI/CD and code extensibility. Values interface safety through dimensionality reduction at interfaces.

• Is obsessive about UX and optimises for this over arbitrary technical goals.

• Is driven, impatient to grow and wants their shot to change the world.

We hire at all levels: our team has new grads and product leaders with 20 years experience.

What to expect in the role

• You’ll work with an incredibly smart team. Like Michael who built a working CPU from logic dates at age 16 and co-founded YC-backed Embark Trucks, the first self-driving vehicle on Canadian roads. Or Souradip, who built an acoustic fall detector using on-device deep learning; he’s also an MB/PhD from Cambridge who’s published in top medical journals.

• You’ll own your projects end to end and ship fast. Like Alex who built ‘Slack for medical teams’ supporting 1000s of channels per organisation and a real time single source of truth for patient data in 4 weeks. Or Dennis who built and shipped a lightning fast cloud document library for clinics in a few days with <100ms traversals through preloading.

• You’ll work on a well-established stack that’s already highly scalable, cost effective, secure and performant with minimal to zero ops.

• You’ll learn new technologies; whatever is needed to solve the problem. We are tech agonistic, and collectively choose the best tools for the job. We’re constantly looking to maximise our productivity and minimise what we call “discounted dev time cost” for shipping features.

Our current stack

We have 2 separate fully functional web apps in prod: one for clinical users and one for patients. Angular, React and Electron, Mixpanel/Posthog for analytics, a fully serverless backend in AWS (Cognito, Appsync GraphQL, Lambda, DynamoDB). We have good functional & unit test coverage and CI/CD.

WHAT WE OFFER

The company should be where you do your life’s best work. We support that with:

• Time off: 25 days’ annual leave plus 8 UK public holidays, with flexible additional time off.

• Health cover: private medical, dental, vision and mental health insurance.

• Parental leave: 12 weeks’ maternity leave at full pay, rising to 24 weeks after two years; 4 weeks’ paternity leave at full pay.

• Pension: 4% employer contributions, with salary sacrifice and 100% of the employer National Insurance savings passed on to you.

• Learning: £1,000 annual budget for your development.

• Fitness: gym subscription matching up to £50 per month.

• Equipment: a high-spec MacBook and a home office budget.

• Time together: two full-team off-sites each year, previous destinations include Mykonos and Mexico.

• Farringdon office: a beautiful new London HQ, with most of the team together at least twice a week.

Everyone is welcome at the company. We strongly believe in building a diverse and inclusive team. If you’re excited by our mission and believe you could do this work well, we’d love to hear from you, even if your experience doesn’t match every point above. If adjustments would help you participate fully in the interview process, please let us know.