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, it reached a $1B valuation in 2024. With 500M+ downloads, 77M+ monthly users, and 6M paid subscribers, Flo offers the highest-rated experience in the App Store’s health category. It focuses on AI-powered, privacy-first, clinically backed digital health solutions to help users better understand their bodies.

Flo is hiring an Engineering Manager for the Data Science Team in London. This role leads the Predictive Growth Optimization team, developing ML models that power user acquisition strategies, predict lifetime value, and optimize an annual $25M+ marketing spend. The position blends hands-on technical leadership with people management, focusing on critical models reused across user acquisition, AdTech, personalization, and financial forecasting.

Lead and develop a team of 4+ ML and Backend engineers by hiring, mentoring, and setting technical direction. Own the predictive lifetime value (pLTV) strategy and architecture of core models informing user acquisition decisions. Build production ML systems including marketing mix models and real-time forecasting handling millions of predictions daily. Collaborate cross-functionally with Growth, Product, and Finance teams. Guide MLOps infrastructure, monitoring, and iteration. Stay hands-on with modeling and technical problem-solving as needed.

7+ years of applied ML experience in production, 4+ years managing technical teams in ML or data science. Expert in ML fundamentals including supervised/unsupervised learning, time series, and causal inference. Experience with ML frameworks like PyTorch, TensorFlow, scikit-learn, and CatBoost. Experience in growth analytics, attribution modeling, or marketing effectiveness. Knowledge of user acquisition funnels and retention optimization. Skilled in translating business requirements to technical roadmaps and communicating complex models to executives. Experience deploying ML models at scale, understanding MLOps practices, data engineering fundamentals, and cloud platforms.

Experience with Marketing Mix Modeling, attribution, or ad tech. Background in consumer tech, mobile apps, or health tech. Knowledge of privacy-preserving ML techniques and A/B testing methodology.

Flo is a fast-moving, mission-led, product-driven team that values focus, ownership, and debate. The team cares about craft and shipping with purpose while raising the bar continually.

Competitive salary and annual reviews. Participation in Flo’s performance incentive scheme. Paid holiday, sick leave, and female health leave. Enhanced parental leave and pay for various types of parents. Accelerated professional growth with learning support. Flexible office and home working, including up to 2 months a year working abroad. A 5-week fully paid sabbatical at 5 years of service. Flo Premium for friends, family, and additional health, pension, and wellbeing perks.

Flo values differences, hiring based on merit and skill, and is an equal opportunity employer welcoming applicants from all backgrounds. Privacy notice for job applicants is available on their website.