Senior Data Scientist, Member Lifecycle

Brief info about Vinted Our mission is to make second-hand the first choice, and we're looking for people who want to help us get there. Every day, we work together to help our members buy and sell pre-loved clothing and lifestyle items, giving each piece a second life – or even a third. The Vinted Group is made up of three business units that support this mission: Vinted Marketplace is Europe’s leading platform for second-hand fashion and a go-to destination for all kinds of pre-loved items, with a growing range of categories. Our platform connects millions of members across 20+ markets, helping great items find a new life. Vinted Go enhances the shipping experience with a vast network of over 500,000 pick-up and drop-off points, partnering with more than 60 carriers across Europe, with added services like item verification for peace of mind on high-value pieces. Vinted Pay is the newest part of the Vinted Group, dedicated to bringing secure, reliable payments to buyers and sellers across Europe. Seamlessly integrated into the Vinted app, it helps keep every transaction safe, efficient, and easy for our members. Founded in 2008 in Lithuania, Vinted began as a way for friends to find new homes for clothes they no longer needed. In 2019, we became Lithuania's first unicorn! Today, our headquarters remain in Vilnius, and we've grown with offices across Europe, supported by a team of over 2,000 people. Information about the position Vinted sends over a billion messages every month to millions of users , across multiple channels (e.g. push, email, in-app) and with multiple goals (marketing, transactional, legal). We are looking for an ambitious Data Scientist to join an early stage initiative to build Vinted’s communication decisioning layer from the ground up: A unified "brain" that evaluates eligible message candidates and decides whether to send, hold, drop, bundle, when to deliver, and through which channel , or whether silence is the most valuable action to protect long-term user trust. In this role, you will take ownership of the core ML algorithms, uplift models, and policy optimisation frameworks that govern Vinted’s communication flows. In this position, you’ll Own core decisioning & modelling logic: Design, prototype, and refine multi-objective recommendation and delivery models (e.g., contextual bandits, uplift modelling, ranking, capping) that govern message selection, timing, and channel routing. Formulate the optimisation problem : Develop policies that maximise long-term member value and marketplace health (GMV, active buyers/sellers) while strictly controlling negative externalities like unsubscribes and notification fatigue. Evaluate impact : Establish reliable offline policy evaluation, and partner with Decision Scientists to design and run large-scale global holdout experiments, attributing incremental business impact and engagement quality. Bridge science to production : Collaborate closely with Engineers and Product to deploy prototype models into production pipelines. Build the future : Contribute to the long-term vision of a Vinted Communication Recommender. About you Have a strong technical background through a degree in Computer Science, Mathematics, Statistics, Data Science, Engineering, or another quantitative field Hands-on experience developing and deploying machine learning algorithms in a product company or research setting Well-versed in Python and SQL, BigQuery is an advantage Have a structured, meticulous way of working when trying out different approaches towards a set goal Be a conscious team player who understands when their work touches that of other team members and proactively aligns with them Good at explaining details of machine learning methods to lay audiences Solid written and spoken English Advantage : Experience with recommendation, ranking or retrieval-based algorithms Advantage : Experience working in e-commerce, two-sided marketplaces, or digital advertising Advantage : Experience…