AI/ML Engineer

<p style="min-height:1.5em"><strong>Build the AI therapist that delivers end-to-end CBT to patients in the US: live, clinically supervised, and measured on whether people actually get better.</strong></p><p style="min-height:1.5em"><strong>About Limbic</strong></p><p style="min-height:1.5em">Limbic’s vision is to ensure the highest quality therapy is accessible to everyone, everywhere.</p><p style="min-height:1.5em">Limbic has supported more than 820,000 patients across the UK and the US. We are used in over 50% of NHS Talking Therapies services, which makes us the largest-ever deployment of generative AI for direct patient care, and our AI now delivers end-to-end therapy to patients in the US under the supervision of licensed clinicians.</p><p style="min-height:1.5em">Safety and science come first. We are the only AI mental health chatbot with UKCA Class IIa medical device certification, and the first AI-led mental healthcare company selected for the FDA’s TEMPO pilot. Our results are published in leading scientific journals: in a randomised, double-blind trial published in Nature Medicine, our AI agents scored higher than licensed CBT therapists on a standard measure of therapy skill.</p><p style="min-height:1.5em"><strong>The Role</strong></p><p style="min-height:1.5em">As an AI/ML Engineer, you will sit at the intersection of computational psychiatry, clinical science, and software engineering. You will join the product team building our AI therapist: a voice agent that delivers structured, evidence-based CBT over the phone to adults with depression and anxiety, with licensed clinicians overseeing every patient’s care.</p><p style="min-height:1.5em">The product is live and growing week on week, so your work reaches real patients quickly. You will own problems end to end: frame them with clinicians and product managers, ship a change, measure whether it helped, and iterate. Our AI products are built on shared platforms for agents, evaluation and safety, so what you build here is reused across Limbic.</p><p style="min-height:1.5em"><strong>What You’ll Do</strong></p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Improve how our AI therapist runs sessions, from session structure and case formulation to therapeutic techniques and continuity across a course of treatment, working closely with clinicians.</p></li><li><p style="min-height:1.5em">Strengthen the safety systems that protect patients in real time, including risk detection and how the agent responds when risk is disclosed.</p></li><li><p style="min-height:1.5em">Build evaluations and LLM-as-judge autolabellers, validated against clinician labels, so we know quickly and reliably whether a change made care better or worse.</p></li><li><p style="min-height:1.5em">Make voice conversations feel natural: responsive, well-paced, and able to recover gracefully when a conversation goes off script.</p></li><li><p style="min-height:1.5em">Help patients stay with their treatment long enough to recover, through AI features such as well-timed session reminders and clear expectations about what therapy involves, and test what works with experiments.</p></li><li><p style="min-height:1.5em">Optimise how we collect outcome measures such as PHQ-9 and GAD-7, including the methods, timing and predictive modelling of recovery.</p></li><li><p style="min-height:1.5em">Ship changes safely through incremental rollouts, automated testing and a clinical sign-off process built for a regulated medical device.</p></li></ul><p style="min-height:1.5em"><strong>What You’ll Bring</strong></p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">You must meet one of the following educational and experience backgrounds:</p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">A PhD in Computational Psychiatry or a related field, coupled with demonstrated industry experience in Data Science, Product, or ML engineering.</p></li><li><p style="min-height:1.5em"><strong>OR</strong> A BSc/MSc in a Computational Psychiatry related field (research focus) plus 2 years of experience in ML engineering or Data Science within an Engineering/Product Development environment.</p></li></ul></li><li><p style="min-height:1.5em">Proficiency in either Python or TypeScript/JavaScript.</p></li><li><p style="min-height:1.5em">Experience building LLM-powered features and a track record of eval-driven development.</p></li><li><p style="min-height:1.5em">An expert approach to hypothesis-driven work, with a track record of balancing product development with scientific rigour.</p></li><li><p style="min-height:1.5em">Experience using Machine Learning in a production environment or via high-impact scientific publications (e.g., predictive modelling, reinforcement learning).</p></li><li><p style="min-height:1.5em">Experience modelling text/language data, including building LLM classifiers and using vector-based methods.</p></li><li><p style="min-height:1.5em">Experience modelling longitudinal data and working with databases (SQL or NoSQL).</p></li><li><p style="min-height:1.5em">A strong understanding of evidence-based mental health care (such as Cognitive Behavioural Therapy) and a deep interest in the causal mechanisms that drive therapeutic benefit.</p></li><li><p style="min-height:1.5em">A bias to action: you break big problems into pieces you can ship within a week, and you are comfortable making decisions with incomplete information.</p></li><li><p style="min-height:1.5em">Proficiency with version control systems, preferably Git.</p></li><li><p style="min-height:1.5em"><em>Ideal but not required:</em> Experience building an LLM agent harness or real-time voice AI.</p></li><li><p style="min-height:1.5em">The ability to work from our London (Spitalfields) office on Tuesdays and Thursdays, with the flexibility to work remotely or from the office on other days of the week.</p></li></ul><p style="min-height:1.5em"><strong>Benefits &amp; Wellbeing</strong></p><ul style="min-height:1.5em"><li><p style="min-height:1.5em">Competitive salary and equity share options.</p></li><li><p style="min-height:1.5em">An amazing office in central London (Spitalfields) for our collaborative team days on Tuesdays and Thursdays, paired with a flexible/hybrid working model on Mondays, Wednesdays, and Fridays.</p></li><li><p style="min-height:1.5em">25 days PTO plus bank holidays.</p></li><li><p style="min-height:1.5em">Company pension scheme (UK).</p></li><li><p style="min-height:1.5em">Enhanced parental leave packages (UK).</p></li><li><p style="min-height:1.5em">Support with purchasing work-related books and materials.</p></li><li><p style="min-height:1.5em"><strong>Quarterly Life Days:</strong> Enjoy 4 paid days off per year (one each quarter) to use whenever you choose to relax, recharge, or take care of personal matters.</p></li><li><p style="min-height:1.5em"><strong>Mental Health Support:</strong> Access to dedicated mental health support services.</p></li></ul><p style="min-height:1.5em"><em>We encourage women and individuals from diverse backgrounds to apply and join our team. We believe in creating an inclusive and supportive work environment where everyone can contribute their best.</em></p><p>Find <a href="https://www.arbeitnow.co.uk">Jobs in United Kingdom</a> on Arbeitnow</a>