Senior Product Engineer

About the Role

Junction builds the infrastructure layer for diagnostic healthcare: making patient data from wearables and lab tests accessible, automated, and actionable at API level. They're already streaming time-series data from 3M+ wearables per second and processing 4M+ lab tests annually across all 50 US states.

The next target is 40 million diagnostics in 2026, and this role exists because getting there requires expanding both the diagnostics API and the customer-facing products built on top of it. The engineering team is small — six people today, growing to around 18 by end of year — so the scope each engineer owns is large.

You'll work full-stack across Junction's two product verticals: wearables and lab testing. Day to day, that means designing and building new features end-to-end — customer dashboards that let healthcare companies self-serve and order lab tests for their patients, APIs that surface actionable diagnostic data, and interfaces that translate complex medical information into something a clinician or patient can act on.

You'll speak directly with customers, pull on usage data, and iterate based on what you learn. Because Junction operates in healthcare, where a bad decision has consequences for real patients, you'll work within domain constraints and alongside subject matter experts — this isn't a "move fast and break things" environment, and the engineers who thrive here combine strong product instincts with the discipline to apply them carefully.

What They're Looking For

• You have senior-level product engineering experience at a startup where you shaped what to build, not just how — with a track record of owning and shipping full-stack features end-to-end from spec to production.

• You're comfortable across a modern full-stack: TypeScript and Next.js on the frontend, Python or Go on the backend, and operating against cloud infrastructure at the scale of millions of daily transactions (GCP or equivalent).

• You can take a messy, underspecified problem — the kind that arrives with complex insurance rules, lab ordering constraints, or incomplete patient data — and turn it into a clear plan and shipped software without waiting for a complete brief.

• You care about how people actually use what you build: you proactively seek out customer feedback, design against real usage patterns, and know the difference between "technically correct" and "actually solves the problem."

• You're driven by the problem Junction is working on, and you can speak with specificity about your interest in healthcare — the founders go deep on this in the interview process, and they're looking for people who genuinely care about the impact on patients' lives.