Senior Full-Stack Engineer

Own the web product, the commerce integrations and the services behind them, end to end.

Humotron reads data from the trackers people already wear, works out what it shows, and matches each person to products from a large index, all without a brand ever seeing the data. That runs today across a website, iOS and Android apps and an API, with a Shopify app on the way.

Your job is to own the web and commerce side of that, end to end: the React front end, the Node.js services and MongoDB behind it, the integrations with commerce platforms, and the pipeline that gets it all to production safely. You will work alongside our existing developers and directly with the founder, who built much of the first version.

We are a small team, so you will make real decisions about architecture, quality and what to build next. We use AI coding tools heavily, which makes clear thinking, careful review and good tests more valuable, not less.

• Build and maintain features across the React website and the Node.js and MongoDB services behind it.
• Own our commerce integrations, starting with the Shopify app, then other platforms and the hosted match page.
• Develop the public API and the developer experience around it: keys, sandbox, documentation.
• Keep the boundary that defines us intact: health data and customer identity are held apart, and brands never receive health data.
• Work on the integrations with tracker makers’ APIs and the processing of the data they return.
• Improve testing, deployment, monitoring and performance so that we can ship often without breaking things.
• Review code, including code written with AI tools, with care for security and privacy.
• Work with product, data and partnerships to decide what is worth building, and say so when something is not.
• Write things down: decisions, set-up, and how to run what you build.

• Strong experience building and running production web applications with React and Node.js, and with a document or relational database.
• Experience designing APIs that other companies build on.
• Experience with authentication, OAuth and handling personal data properly.
• Good habits around testing, code review, deployment and incident handling.
• The judgement to choose a simple solution, and the ability to explain a technical trade-off to someone who is not an engineer.
• Comfort owning a whole area, from the first design to keeping it running.
• Clear written English, since much of our work is done in writing.

• Experience building Shopify apps or integrations for other commerce platforms.
• Experience with health or wearable data, or with other regulated or sensitive data.
• Experience with iOS or Android development.
• Experience with recommendation, search or ranking systems.
• Experience with privacy-preserving design or security review.

• A real system already in production, with real decisions still to make.
• A privacy design that is an interesting engineering problem, not a policy document.
• Wide scope: web, API, commerce platforms and data, with a say in what comes next.
• You work directly with a technical founder, and your decisions are used.
• Share options, so that you own part of what you help build.

Humotron helps people choose wellness products from their own data. A person connects the tracker they already wear, and we match them to the supplements, skincare, footwear, habits and programmes that suit what their data shows, with the reason for each one. For businesses, the same matching runs inside their own store, practice or benefits programme, and they never see or hold anyone’s health data. Humotron is a wellness service, not a medical one.

The product is built. It is live for individuals, and the business products are rolling out now. Humotron Ltd is a new company: founded by one person, built so far with a small development team. These are its first seven hires, and they start in January 2027. We are having first conversations now.