Senior Backend Engineer - Do Health

Salary: £63,000 - 69,000 per year

Requirements:

• 5–8 years of backend experience with strong fundamentals
• Experience at a startup or scale-up where you genuinely owned things
• Architectural thinking and the ability to hold end-to-end technical conversations about systems youve built, including trade-offs and lessons learned
• A track record of shipping reliable systems, including infrastructure that keeps products up and running
• Comfort making judgement calls in ambiguous situations
• Confident, responsible use of AI tools in your workflow
• Strong TypeScript / Node.js experience is nice to have, but we are also open to excellent engineers from Go, Kotlin, Python or similar backgrounds
• Experience scaling systems to high user volumes is nice to have
• Exposure to ML/AI systems in production is nice to have
• Healthcare or regulated-industry experience is nice to have

Responsibilities:

• Own major backend features end-to-end, from design through build, ship, monitoring, and iteration
• Shape architecture alongside our lead engineer and make real technical decisions based on what works
• Scale our blood testing infrastructure across the UK and internationally
• Build production AI systems, including personalisation engines that act on longitudinal health data at scale
• Improve reliability, observability, and the foundations the product depends on as it grows
• Work directly with product, design, and clinical teams

Technologies:

• AI
• Backend
• Kotlin
• Mobile
• Python
• TypeScript
• NodeJS

More:

We are Do Health, a mobile-first preventative health product co-founded by Dr Rangan Chatterjee and built as an independent startup inside Voy. Voy is one of the UKs fastest-growing digital health companies, with 300M+ revenue, doubling next year, and around 2x year-on-year growth across mens health, metabolic health, menopause, hormonal health, TRT, dermatology, and more. Do Health is our next chapter: the first product designed not to treat illness, but to prevent it. Our product combines regular blood tests, longitudinal health data, behaviour-change science, and AI personalisation to help people make better lifestyle decisions over time. We already run AI systems in production at a scale very few UK companies match. You would join a 10-person team and work directly with our lead engineer, with no layer of management between you and the work. We offer genuine equity, startup velocity with grown-up backing, direct access to leadership, a high technical bar from day one, and a short hiring process. The role is based in London with a hybrid working pattern of around 3 days per week in person, and compensation is competitive.

last updated 36 week of 2026