Founding Full Stack Engineer

🚀 About the company

We're turning smartphones into health screening devices. 2 minutes. No hardware. 60+ biomarkers — from face, voice, eyes, and behaviour.

YOU(th) is building the infrastructure for mass preventive care. We just closed our seed round backed by Callisto Health, Caesar VC, Adesso Ventures, Antler, Index Ventures Magnetic Fund, Lakestar Halo, and unicorn founders from Alan and HomeToGo.

We're looking for a Founding Senior Full-Stack Engineer to help shape what we build and how we build it.

What you'll do

You'll work directly with our founding team. You'll develop backend services, own product features end-to-end, and help make architectural decisions that shape the product for years.

This is a founding role. We expect initiative, ownership, and opinions.

What we are offering

We just closed our seed round and we are rebuilding the founding team around a small, elite group. This is the moment for the Founding Engineers to shape technical decision that matters. Architecture, AI strategy, team culture. All of it is yours to influence.

What we are offering:

• Equity stake: you are a Founding Engineer, not a “normal” hire
• Competitive salary from day one
• Fresh funding, runway to build the right way
• A bold vision, Unlocking prevention for 8 billion people, leveraging smartphones as an health screening tool
• A founding team that moves fast and wants a technical equal at the table, not an executor

What we're looking for

• 5+ years in software development
• Strong backend skills - ideally in Python and FastAPI
• Frontend experience with TypeScript, Next.js, React
• Previous startup or high-ownership environment experience
• Comfortable with CI/CD, SDLC, and building things that scale

Nice to have:

Experience in regulated industries (healthcare, banking), knowledge of Flutter, or familiarity with GCP.

Attitudes we expect:

High agency: You don’t wait for instructions. You take responsibility and act.

Multi-domain fluency: Your are able to think across domains, all at once. You refuse to think narrowly in one lane.

Builder’s instinct: You make things with their own hands. If something breaks, you fix it. If something’s missing, you prototype it.

Comfort with chaos: Agents fail, models drift, things break. You stay calm, and adapt.

Truth-seeking over status-seeking: You share information, including failures. Everything is public and out in the open.

Low ego… experimentation is failure. You are able to separate themselves psychologically from the product.

..but not low self-worth: if you believe you are destined to fail you will handicap yourself before you even start. You have confidence to move forward in the first place, without fear of failure.

Internal locus of control: You operate as if everything is their responsibility, even things they don’t formally own. If something is broken, if someone is stuck – you step in.

Systems intuition: You sense when a workflow, team, or agent network feels “off.” You can diagnose bottlenecks instinctively.

Full JD: https://youthai.notion.site/Founding-Senior-Full-Stack-Engineer-2d15a55c73d7808cb645ec7f857278c7?pvs=74