Machine Learning Engineer

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Limbic’s vision is to make the highest quality therapy accessible to everyone, everywhere. We deploy AI responsibly, augment clinical care, and reduce barriers to therapy at scale. Limbic is already used in over 40% of Talking Therapies in the NHS, making us the largest-ever deployment of generative AI for direct patient care. Limbic is safe and effective after gaining UKCA Class IIa certification, the only AI mental health chatbot to do so.

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• Design, build, and deploy ML‑powered features end to end, including:
  
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  • Architecture of systems combining LLM features with in‑house safety guardrails and clinical ML models, working with OpenAI, Anthropic, Google, and in‑house self‑hosted Llama instances.
    
  • Implementing and refining evaluation methodologies that combine user testing, LLM evals, and clinical trials.
    
  • Implementing continuous monitoring strategies for production deployments.
    
  
  
  
• Collaborate with team members through code review and contribute to engineering best practices.
  
• Integrate with application engineers at the interface of application and ML engineering, working with security, orchestration, and data teams.
  
• Help build and tune custom models.
  

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• Architect and deploy a voice agent for mental health service phone calls, integrating safety guardrails and continuous monitoring.
  
• Collaborate with clinicians to develop an AI triage system that conducts text‑based patient intake conversations, providing clinicians actionable insights before appointments.
  
• Train, evaluate, and deploy models to detect problematic user interactions.
  
• Build and run experiments comparing the therapeutic sessions powered by voice versus text‑based AI agents.
  

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• 2+ years of industry machine learning experience.
  
• Availability during standard business hours for teams across Europe (UTC to UTC+3).
  
• Experience working with LLM features.
  
• Strong Python ability and experience with at least one backend Python framework (e.g., FastAPI).
  
• Solid understanding of statistics in the context of ML model evaluation and user activity analytics.
  
• Experience with databases (SQL or NoSQL).
  
• Familiarity with cloud platforms (AWS, GCP, Azure) and containerization technologies (Docker).
  
• Proficiency with version control systems, preferably Git.
  
• Interest in the mental healthcare space.
  
• Experience with Typescript / Javascript is a bonus.
  
• Limbic can not provide visa sponsorship.
  
• Ability to work from London office one day per week is preferred.
  

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• Central London office with flexibility for office and WFH.
  
• 25 days PTO.
  
• Pension scheme.
  
• Enhanced parental leave packages (UK).
  
• Equity share options.
  
• Support for purchasing work‑related books and materials.
  
• Quarterly life days (4 paid days off per year).
  
• Access to mental health support.