Senior Data Scientist, Help Experience

Help Experience (HEX) supports 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.

• 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 metrics like Automation Rate, Containment, and Chatbot CSAT.

• You have a strong technical background and hands-on experience developing machine learning algorithms.
• You are highly skilled in Python and SQL.
• You write clean, maintainable, and structured code that serves as an inspiration for others, valuing reproducibility, clarity, and performance.
• You can persuasively explain complex technical concepts and their business implications to non-data stakeholders.
• Fluent in written and spoken English.

Nice to have

• You prefer an iterative approach and can read a research paper and translate it into clean, replicable code.
• You understand that behind every data point is a real member trying to get help.

• 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
• Pension plan with flexible contribution options and a matching contribution from Vinted
• Confidential Employee Assistance Program (EAP) for you and your family
• Frequent team-building events
• A personal monthly budget for shopping on Vinted
• A dog-friendly office
• In Vilnius office: Gym & in-house meals at friendly prices
• In Kaunas office: a monthly lunch allowance, and a once-a-week provided in-house lunch and breakfast