Principal Software Engineer

The job A stealth healthcare AI startup is building agents that can do the work of GPs: diagnose, triage, communicate with patients, and handle the data layers that sit underneath all of it. The mission is blunt - make healthcare accessible by automating the parts that do not require a human. You will be one of the engineers who build the actual system, not a proof of concept. You will deploy it into hospitals and clinics. You will be responsible for whether it works in production, under real conditions, with real patient data. This is a Python-heavy, distributed systems role. It is not a research role and it is not an ML theory role. It is a build-and-ship role in a domain where getting it wrong has consequences. What you will actually do Deploy and refine AI-driven patient communication and triage systems directly with hospitals and clinics. Architect and scale agent orchestration systems built on LLMs and agentic frameworks. Build and maintain secure healthcare data layers with low-latency voice and video capabilities. Scale distributed systems under real clinical load. Work in a small team which means you own things end to end, not hand them off. What the real challenge is Healthcare AI has a gap between demo and production that is wider than almost any other domain. The challenge here is not building something that works in a notebook and it is building something that works reliably in a hospital, handles sensitive patient data correctly, performs under latency constraints, and does not fail silently when it matters most. You need to be comfortable with ambiguity, with incomplete specs, and with the weight of building systems that affect real patients. What you need 5+ years of senior engineering experience building complex, production-grade systems. Strong Python skills — this is the core language, not optional. Proven ability to take ambiguous requirements and ship scalable, working solutions. Hands-on experience with LLMs, agent-based architectures, or distributed AI systems in production. Experience working in healthcare, fintech, or another high-stakes regulated domain is a strong advantage. High ownership mentality in a lean team and no one is going to manage your tickets for you. Stack Python (primary) Go, Rust, or TypeScript (secondary and bring what you know) LLMs and agentic frameworks Distributed systems and cloud infrastructure (AWS or equivalent) Low-latency voice and video Secure healthcare data layers What this role is not Not a research or experimentation role. Not a large eng team where you own one microservice and nothing else. Not a role where the stack is locked and the architecture is already decided. Not a role for someone who needs clean, well-defined requirements to get started. Compensation and setup €100,000 to €200,000 depending on experience, plus equity. Remote-friendly, full-time, London-based company. The client is in stealth — you will learn more about the company in the first conversation. Apply To This Job