Machine Learning Engineer (Recommendations) in London

Healf was founded by two brothers - Max and Lestat - with a relentless drive to reshape health and wellness. Their journey has been fuelled by hard work, intensity, and a commitment to build something transformative. Like all of us, they’re here to make a lasting impact.

At Healf, we’re not just a company, we’re a movement. Founded by two brothers whose own wellbeing journeys inspired our mission to empower others, Healf is built on grit, determination, and a shared understanding of the power of wellbeing. Our culture is grounded in The Healf Standard—five principles that define how we work and win:

• We Work Harder Than Anyone Else: Building something that improves lives takes long hours, grit, and sacrifice, but we thrive on it. We all feel energised by what we’re building.
• Never Settle: We challenge the status quo and push ourselves to be better every day. We never settle for mediocrity or the idea that something can’t be done.
• Obsession Over Talent: Talent alone isn’t enough—relentless curiosity and a drive to grow set us apart.
• The Healf Lifestyle: We live what we preach—our personal commitment to wellbeing fuels our professional productivity.
• Stronger Together: Everyone owns their lane, but we run as a unit.

With Healf Zone on the horizon, we’re entering the next phase of our journey: closing the loop on health with personalised, preventative care that unlocks longevity and optimised wellbeing. This is your chance to help build something that’s not only extraordinary, but a first of its kind.

The Role

We’re looking for a Machine Learning Engineer – Recommendations to help build the foundation of Healf’s personalisation and intelligence platform. You’ll design, train, and deploy recommendation models that power dynamic merchandising, personalised discovery, and tailored health journeys across web, app, and beyond. This is a highly cross-functional role working closely with Product, Data, and Engineering to turn raw data into real-time insights and experiences. Over time, you’ll also contribute to developing predictive algorithms that help users make better health decisions — forming the intelligence layer of Healf’s long-term vision: a wellbeing platform powered by AI and data.

Where You’ll Make An Impact

• Build and evolve Healf’s recommendation engine, driving personalised product discovery and dynamic merchandising across web and app.
• Develop and deploy machine learning models that optimise product relevance, content ranking, and user engagement.
• Partner with Product and Data teams to define and capture the signals that power our personalisation logic.
• Contribute to the development of predictive algorithms that leverage data from Healf Zone, Helix, and user behaviour to anticipate customer needs.
• Collaborate with Engineering to integrate ML systems into production pipelines and ensure scalable performance.
• Experiment with LLM-based retrieval and recommendation architectures.
• Continuously measure, evaluate, and optimise model performance through experimentation and A/B testing.
• Help shape the roadmap for Healf’s broader wellbeing intelligence platform — connecting data, health insights, and user intent.
• Champion data quality, ethics, and compliance in all model design and deployment processes.

What You’ll Bring

• 4–6 years of experience as a Machine Learning Engineer or Data Scientist, ideally within eCommerce, consumer tech, or recommendation systems.
• Strong background in building and deploying ML models using Python, PyTorch, TensorFlow, or similar frameworks.
• Proven experience with recommendation engines, ranking algorithms, or personalisation pipelines.
• Familiarity with LLMs, embeddings, and NLP techniques for recommendation and content matching.
• Proficient in SQL and data manipulation tools; experience working with modern data stacks (e.g., dbt, Snowflake, BigQuery).
• Solid understanding of MLOps practices — model versioning, CI/CD, and production monitoring.
• Comfortable working across product and engineering teams to translate business goals into model objectives.
• Experience with experimentation, A/B testing, and performance measurement.
• Curious, self-directed, and excited to build the intelligence layer behind the future of personalised wellbeing.

Why Join Healf

• Do your life’s best work: Build something that matters, with a team that moves fast and aims high.
• Surround yourself with A+ talent: You’ll work with high-performers who care deeply and raise the standard every day.
• Be a builder: This isn’t a cog-in-the-machine role. You’ll help shape our voice, culture, and growth.
• Wellbeing is the lifestyle: From office yoga to Healf Zone insights, everything we do is rooted in our pillars: EAT MOVE MIND SLEEP.
• Premium Wellhub Membership: Unlimited entry to 1000's of gym, yoga, & fitness studios.
• Exclusive Healf Perks: 50% off all Healf products plus discounted Healf Zone blood testing.
• Nest Pension: Secure your future with our pension contributions.
• Wellbeing-Focused Workspace: Incredible Hammersmith office with great natural lighting.
• Team Connection: Annual company-wide retreat to recharge and bond.