Senior BackEnd Engineer (Do Health)

Requirements

• 5–8 years of backend experience with strong fundamentals. We care more about depth than years
• Experience at a startup or scale-up where you genuinely owned things
• Architectural thinking. You can hold an end-to-end technical conversation about systems you’ve built — what trade-offs you made, what broke, what you’d do differently
• A track record of shipping reliable systems. Not just features — the boring infrastructure that keeps them up
• Comfort with judgement calls in ambiguous situations. Most decisions here don’t have a clear right answer
• Confident, responsible use of AI tools in your workflow. Not “vibe coding” – using them as a force multiplier where they help, ignoring them where they don’t
• (Desirable) Strong TypeScript / Node.js experience (it’s our primary stack, but we’ll happily hire someone excellent in Go, Kotlin, Python or similar)
• (Desirable) Experience scaling systems to high user volumes
• (Desirable) Exposure to ML/AI systems in production
• (Desirable) Healthcare or regulated-industry experience

What the job involves

• We’re hiring the a Founding Backend Engineer at Do Health – a mobile-first preventative health product co-founded by Dr Rangan Chatterjee, built as an independent startup inside Voy
• You’d join a 10-person team, partnering directly with our lead engineer on the backend
• There’s no layer of management between you and the work. What you ship in month one is what users get
• Own major backend features end-to-end – design, build, ship, monitor, iterate. Not “contribute to” – own
• Shape architecture alongside the lead. Real technical decisions, made by you, kept or changed based on what works
• Scale our blood testing infrastructure across the UK and internationally as we expand
• Build production AI systems – personalisation engines that act on longitudinal health data at scale
• Improve reliability, observability, and the foundations that everything else depends on as the product grows
• Work directly with product, design, and clinical teams. No tickets thrown over walls

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