Data Scientist, Help Experience

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  Help Experience (HEX) supports tens of millions of Vinted members across 20+ markets. When members encounter an issue—from shipping delays to payment questions—we want to resolve it as fast, effortlessly, and accurately as possible. We are looking for a Senior Data Scientist to join the Ember team within the Help Experience domain. Ember is building the next generation of AI-powered support at Vinted. Our mission is to serve scalable support automation that users appreciate. We build and scale our conversational Virtual Assistant and automated resolution systems, transforming support from traditional ticketing into instant, conversational problem-solving. By resolving issues autonomously and helping members get back to buying and selling with confidence, Ember directly reduces operating costs and manual ticket volume supporting Vinted’s mission to make second-hand the first choice worldwide. In this position, you’ll  Build Conversational AI & Agentic Systems: Design, develop, and scale LLM-powered virtual assistants and agents capable of multi-turn dialogue, understanding nuanced member intent, and reasoning over complex marketplace policies and real-time transaction data. Drive Autonomous Resolution & Decisioning: Build decision systems and classification models that know when an issue can be safely and autonomously resolved (including executing automated actions like cancellations, tracking updates, or refunds) versus when to seamlessly hand off to human support specialists. Leverage Modern GenAI & RAG Architectures: Implement and optimize Retrieval-Augmented Generation (RAG), embeddings, prompt engineering, and fine-tuning techniques to deliver accurate, context-aware answers across multiple languages and noisy conversational inputs. Establish Robust Evaluation & Guardrails: Design offline and online LLM evaluation frameworks (measuring policy compliance, hallucination mitigation, response safety, and containment quality) to ensure automated interactions are dependable and aligned with brand guidelines. Ship to Production at Scale: Partner closely with Backend Engineers and ML Platform teams to deploy and serve models in low-latency, high-throughput production environments, monitoring for drift and performance degradation in real time. Partner for Impact: Collaborate with Product Managers, Decision Scientists, and Customer Support Operations to identify high-impact automation opportunities, design rigorous A/B experiments, and directly move core metr