Machine Learning Engineer

500M+ downloads. 80M+ monthly users. A decade of building – and we’re still accelerating.Flo is the world’s #1 health & fitness app worldwide on a mission to build a better future for female health. Backed by a $200M investment led by General Atlantic, we became the first product of our kind to reach a $1B valuation in 2024 – and we’re not slowing down.With 7M paid subscribers and the highest-rated experience in the App Store’s health category, we’ve spent 10 years earning trust at scale. Now, we’re building the next generation of digital health – AI-powered, privacy-first, clinically backed – to help our users know their body better.The jobWe are looking for a Machine Learning Engineers to join Flo Health. You will be developing groundbreaking features that leverage our medical expertise, technical skills, rapid adoption of new technologies (like LLMs), product knowledge, and a deep understanding of our users’ needs. If you’re passionate about technology, especially advancements in generative AI, and driven by delivering value to users, we would love to hear from you!Your ExperienceMust have:4+ years of professional experience in the field of machine learningDemonstrated success in building and deploying large-scale machine learning models; experience with large-scale LLM applications is a bonusAbility to devise creative solutions to intricate technical challenges, including experience in systems design with the ability to architect and explain ML/LLM pipelinesStrong Python programming skills for efficient model development and deploymentExperience with both traditional ML and modern LLM frameworksUnderstanding of the entire ML/LLM development process, including CI/CD, version control, testing, MLOps/LLMOps, and agile methodologiesExperience in building and managing data pipelines using tools like Apache SparkExcellent communication skills and ability to collaborate with diverse teamsCommitment to responsible AI practices, including fairness, accountability, and transparencyNice to have:Advanced degree in Computer Science, Mathematics, or a related fieldFamiliarity with statistical and measurement fundamentals and running and evaluating AB testsData visualisation skillsExperience in the MedTech domainWhat you'll be doingYou'll be responsible for:Explore, develop and test complex ML/AI systems to improve female healthWork with state-of-the-art technologies, such as most advanced LLMs and Generative AI approaches, to build solutions that are medically safe and work at scaleWork in a fast-paced environment to quickly build and validate product hypotheses, taking end-to-end ownership of ML/AI productsBuild the future-proof infrastructure for serving Gen AI features at Flo, bringing our AI vision and strategy to lifeConstantly improve our technical capabilities by researching and implementing best practices in the context of the fastly evolving space of LLMsWork in a cross-functional setup alongside other engineering (ML, Backend, QA), product, and analytics teamsAnnual Salary Range (ranges may vary based on skills and experience)130,000—180,000 GBPHow we workWe’re a mission-led, product-driven team. We move fast, stay focused and take ownership – from brief to build to impact. Debate is encouraged. Decisions are shared. We care about craft, ship with purpose, and always raise the bar.You’ll be working with people who take their work seriously, not themselves. It takes commitment, resilience, and the drive to keep going when things get tough. Because better health outcomes are worth it. What you'll getWe support impact with meaningful reward. Here’s what that looks like:Competitive salary and annual reviewsOpportunity to participate in Flo’s performance incentive schemePaid holiday, sick leave, and female health leaveEnhanced parental leave and pay for maternity, paternity, same-sex and adoptive parentsAccelerated professional growth through world-changing work and learning supportIn-person collaboration and work in a hybrid model, with 3 days per week spent in the office5-week fully paid sabbatical at 5-year FloversaryFlo Premium for friends & family, plus more health, pension and wellbeing perksDiversity, equity and inclusionOur strength is in our differences. At Flo, hiring is based on merit, skill and what you bring to the role – nothing else. We’re proud to be an equal opportunity employer, and we welcome applicants from all backgrounds, communities and identities. Read our privacy notice for job applicants.