Senior Data Scientist, Member Lifecycle

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.

• 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.

• 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

Nice to have

• Experience with recommendation, ranking or retrieval-based algorithms
• Experience working in e-commerce, two-sided marketplaces, or digital advertising
• Experience with productionising machine learning models in real-time use cases
• Understanding of user harm/UX impact measurement and safety guardrails in CRM recommender systems.

• The opportunity to benefit from our share options programme
• 25 working days of holiday
• Access to all the tools & tech needed for work
• Home office support: we provide IT workstation equipment and a personal budget of up to 540 for home workplace furniture
• Private health insurance
• Digital mental and emotional health support and Employee Assistant Program (EAP)
• Frequent team-building events
• A personal monthly budget for shopping on Vinted
• The opportunity to spend up to 90 days per year - 21 of which can be spent working outside of the EU - on workation
• A dog-friendly office
• Gym & in-house meals at friendly prices