Senior or Principal Backend Engineer (NodeJS) | 90-120k | Healthtech AI Startup | Hybrid (x3 days pw in Borehamwood - Ldn in Q1 '27)

Senior or Principal Backend Engineer (NodeJS) | 90-120k | Healthtech AI Startup | Hybrid (x3 days pw in Borehamwood - moving to Ldn early 2027)

Role: Senior or Principal Backend Engineer

Salary: 90-120k (+ shares)

Location: x3 days pw in Borehamwood (25–45 min direct train from central London)** plan to move office to Central Ldn early 2027

Tech stack includes: NodeJS, AWS, MySQL, Websockets, Terraform, CDK

Team: CTO (ex Meta) & x1 Full Stack Engineer

This is a seed-stage startup building an AI voice assistant for GP practices. The product answers patient calls, performs triage, and automatically fills in NHS system forms. They’ve recently secured funding and are scaling quickly, with a small engineering team growing from 2 to 4. Currently handling 5,000+ daily calls, integrating with multiple NHS systems, and building scalable backend infrastructure. Early engineers will have significant ownership over system design as the product grows.

Role Responsibilities:

• Build and maintain backend systems, particularly integrating multiple external systems
• Scale infrastructure to support increasing call volumes
• Debug and improve reliability across NHS software integrations
• Work with third-party AI providers

Must-have:

• 6+ yrs experience - must have NodeJS, flexible with background in other languages.
• Database experience e.g. SQL or Postgres
• Embraces using AI tools (e.g. Cursor, agents, automation) in day-to-day development

Nice-to-have:

• Experience working with LLMs, voice tech, or speech-to-text systems