Senior Data Scientist in London

Ready to revolutionize healthcare, making it faster and more accessible than ever before? Founded in 2013 by Dwayne D’Souza, HeliosX was built on a simple but powerful idea: healthcare should be easier to access, faster to receive, and centred around the individual. From day one, we’ve grown without external funding; scaling profitably through technology, disciplined execution, and deep medical expertise. What started as a challenger idea has become one of the most significant healthcare platforms operating globally today.

We’ve earned the trust of millions of people worldwide through category-leading products and well-known brands, including MedExpress, Dermatica, ZipHealth, RocketRX, and Levity. A key driver of our success is vertical integration; we operate our own manufacturing and proprietary products, led by in-house medical teams, researchers, and pharmacists at the top of their fields. In 2025, HeliosX treated more than 1.7 million patients globally and reached £781m in revenue, representing +337% year-on-year growth and cementing our position as the clear market leader in the UK. That growth translates into real-world outcomes: our weight-loss treatments helped patients lose 8.5 million kilograms of excess weight in 2025 alone, contributing to an estimated 1,300 fewer cardiac events. This is growth with measurable, life-changing impact at scale.

Today, we operate across four international markets, with successful launches in Germany and Canada and continued expansion in the US. We were also recently recognised in the Sunday Times Top 100 fastest-growing tech companies, further validation of both our momentum and our ambition.

2026 is a step-change year. Our ambition is to reach £1.6bn in revenue, expand from four to eight global markets and significantly broaden our condition and treatment portfolio. Over the coming years, you’ll help shape HeliosX into a truly world-leading healthcare partner; one that combines scale, speed, and clinical rigour to redefine how personalised care is delivered. Joining HeliosX now means building systems, teams, and products that will define the next decade of digital healthcare, and doing work that genuinely improves lives, at global scale. There’s never been a more exciting time to join HeliosX. Come be a part of making our dream of easier and faster healthcare a reality!

The Opportunity

As a Senior Data Scientist at HeliosX, you’ll shape the future of personalised digital healthcare, building and deploying advanced recommendation models that enhance every step of the patient journey. Working with over a million patient interactions, you’ll turn rich real-world data into actionable insights that improve outcomes and engagement. Partnering closely with Product, you’ll design and test data-driven solutions using our modern stack (Snowflake, Hex, Claude) to deliver truly individualised care at scale. Your work will directly influence how millions of patients receive proactive, personalised support as we set the standard for GLP-1–driven digital health globally.

This is a full-time, permanent role with a hybrid working arrangement. You’ll be expected on-site at our Shoreditch office twice per week, with flexibility to work remotely three days p/w.

What you'll be doing:

• Clinical Prediction Models: Design and implement ML models predicting patient outcomes including medication adherence, treatment response, adverse event risk, and clinical deterioration.
• Patient Stratification: Build risk stratification models identifying patients who would benefit from clinical interventions, medication therapy management, or enhanced monitoring.
• Treatment Optimization: Develop models recommending optimal treatment pathways, medication alternatives, and personalized clinical interventions.
• Healthcare ML Best Practices: Ensure models meet healthcare standards for interpretability, clinical validation, and regulatory requirements (FDA guidance on clinical decision support).
• Product-Embedded Analytics: Lead integration of ML models into customer-facing features improving medication management, adherence tracking, and personalized health recommendations.
• Patient Journey Optimization: Build models that personalize patient experiences across online consultation, prescription fulfillment, and ongoing medication management.
• Real-Time Clinical Insights: Develop streaming ML capabilities providing real-time patient risk alerts and intervention recommendations.
• Cross-Functional Product Leadership: Partner with product managers, clinical teams, and engineers to translate model insights into actionable product features.
• Production ML Infrastructure: Establish robust MLOps practices using MLFlow, SageMaker, or similar platforms for model versioning, deployment, and monitoring.
• Model Performance Monitoring: Implement comprehensive monitoring for model drift, performance degradation, and clinical safety metrics.
• A/B Testing & Validation: Design and execute experiments measuring clinical and business impact of ML-driven interventions.
• Regulatory Compliance: Ensure ML models meet healthcare regulatory requirements including model documentation, validation, and audit trails.
• Data Science Strategy: Define technical roadmap for healthcare ML capabilities supporting product innovation and clinical outcomes.
• Team Development: Mentor data scientists and analysts in healthcare analytics, ML best practices, and clinical domain knowledge.
• Research & Innovation: Lead exploration of cutting-edge techniques including causal inference, survival analysis, and federated learning for healthcare applications.
• Stakeholder Communication: Translate complex ML concepts and clinical insights into clear recommendations for product, clinical, and executive stakeholders.

What you’ll bring to HeliosX

• Machine Learning & Statistical Expertise: Advanced proficiency in supervised/unsupervised learning, time-series forecasting, survival analysis, and causal inference methods. Experience building production ML models for patient stratification, risk scoring, or personalized recommendations. Strong foundation in statistical inference, experimental design, and A/B testing in healthcare contexts. Expertise in model interpretability techniques (SHAP, LIME) critical for clinical decision support. Hands-on experience with healthcare-specific ML challenges (imbalanced datasets, missing data, temporal dependencies).
• Technical Stack & MLOps: Proficiency in Python (scikit-learn, pandas, PyTorch/TensorFlow) and SQL for large-scale data analysis. Experience with modern data platforms (Snowflake, Databricks, or similar cloud data warehouses). Demonstrated MLOps capabilities using tools like MLFlow, SageMaker, Vertex AI, or Azure ML. Experience building real-time ML inference systems and streaming analytics pipelines. Strong software engineering practices including version control (Git), CI/CD, and model monitoring.
• Product & Cross-Functional Collaboration: 3+ years working embedded with product teams translating ML insights into customer-facing features. Track record of successful A/B testing and measuring business/clinical impact of ML interventions. Experience communicating complex technical concepts to non-technical stakeholders (product managers, clinicians, executives). Demonstrated ability to balance scientific rigor with pragmatic product delivery timelines.

Preferred Experience:

• PhD or Master's in Statistics, Computer Science, Biostatistics, Health Informatics, or related quantitative field. Developing clinical prediction models (e.g., readmission risk, adverse events, treatment response, adherence prediction). Experience in digital pharmacy, telemedicine, or direct-to-consumer healthcare platforms. Publication record in healthcare ML or clinical decision support systems. Experience with GLP-1 medications, weight management, or chronic disease management programs. Familiarity with LLM applications in healthcare (Claude, GPT-4) for clinical documentation or patient engagement. Demonstrated knowledge of healthcare regulatory requirements for ML models (FDA guidance on clinical decision support, GDPR, UK MHRA standards).

Why work with us?

At HeliosX, we want to improve healthcare for everyone, and to do this we need a team of brilliant people who share that ambition. We are currently a diverse team of engineers, scientists, clinical researchers, physicians, pharmacists, marketeers, and customer care specialists committed to our mission - but we need more talented folks to join us, if we want to achieve our global ambitions! Aside from working with our all-star team, here are the other benefits of coming on board:

• Generous equity allocations with significant upside potential.
• 25 Days Holiday (+ all the usual Bank Holidays).
• Private health insurance, along with extra dental and eye care cover.
• Employee Pension with Smart Pensions.
• Enhanced parental leave.
• Cycle-to-work Scheme.
• Electric Car Scheme.
• Free Dermatica and MedExpress products every month, as well as family discounts.
• Home office allowance.
• Access to a Headspace subscription, discounted gym memberships, and a learning and development budget (alongside a free Kindle and audible subscription).