Data Science Lead

Vilnius, Lithuania

We’re hiring a Data Science Lead in London to build and lead our Predictive Growth Optimisation team – pioneering ML models that power our user acquisition strategy, predict lifetime value, and optimise our $25M+ annual marketing spend across channels.

This role owns the strategy, development, and continuous improvement of Flo’s pLTV system - a mission-critical model reused across UA, AdTech, personalisation, and financial forecasting. That is the core of the role. Alongside it, you'll stand up a Marketing Mix Modeling (MMM) capability to measure cross-channel effectiveness and inform budget allocation, and develop the algorithms to drive real-time UA campaign management. You'll lead a team building production systems that directly impact our growth trajectory, staying as hands-on as you choose.

What you’ll do

• Lead & develop a team of 6+ ML and Backend engineers - hiring, mentoring, and setting technical direction

• Own pLTV strategy - architect and evolve our core predictive lifetime value models that inform millions in UA decisions

• Stand up MMM - build our Marketing Mix Modeling capability: adstock and saturation modelling, channel contribution, and budget allocation, calibrated against our incrementality experiments

• Power real-time campaign management - develop the algorithms that optimise our UA campaigns across channels in real time

• Build production ML systems - from real-time prediction services handling millions of daily predictions to MMM models

• Drive cross-functional impact - partner with Growth, Product, and Finance to translate business problems into ML solutions

• Shape technical architecture - guide MLOps infrastructure, monitoring, and rapid iteration cycles

• Stay as hands-on as you choose - modeling, architecture decisions, technical problem-solving; your call how deep you go.

What you bring

Technical Leadership

• 7+ years applied ML experience building and deploying models in production

• 4+ years managing technical teams (ML engineers, data scientists, or similar)

• Expert knowledge of ML fundamentals: supervised/unsupervised learning, time series; strong grounding in causal inference

• Experience with modern ML frameworks (TensorFlow, scikit-learn, CatBoost)

Growth & Product Experience

• Experience with growth analytics, attribution modeling, or marketing effectiveness

• Understanding of user acquisition funnels and retention optimization

• Comfortable translating business requirements into technical roadmaps

• Strong communication skills - can explain complex models to executive stakeholders

Production ML Systems

• Experience deploying ML models at scale

• Knowledge of MLOps practices: model versioning, monitoring, automated retraining

• Understanding of data engineering fundamentals and cloud platforms

Nice to have

• Hands-on experience building Marketing Mix Models end to end, Bayesian or regression based

• Background in consumer tech, mobile apps, or health tech

• Knowledge of privacy-preserving ML techniques and A/B testing methodology

What you'll get

We support impact with meaningful reward. Here’s what that looks like:

• Competitive salary and annual reviews

• Opportunity to participate in Flo’s performance incentive scheme

• Paid holiday, sick leave, and female health leave

• Enhanced parental leave and pay for maternity, paternity, same-sex and adoptive parents

• Accelerated professional growth through world-changing work and learning support

• In-person collaboration and work in a hybrid model, with 3 days per week spent in the office

• 5-week fully paid sabbatical at 5-year Floversary

• Flo Premium for friends & family, plus more health, pension and wellbeing perks

Salary Range - gross per month (ranges may vary based on skills and experience):
€9.000 - €11.000 EUR