Senior Data Scientist (AI)

Location: Berlin, Germany. Hybrid work with 2 recommended office days per week; remote work is available through the workation policy for up to 90 days per year in the EU, including 21 days globally, or 21 days worldwide for non-EU citizens.

Annual gross salary: €74,000–€100,100 EUR.

Company

hirify.global is a European second-hand marketplace connecting millions of members across 20+ markets, with headquarters in Vilnius and offices across Europe.

What you will do

• Design, develop, and scale LLM-powered virtual assistants and agents supporting multi-turn dialogue, member-intent understanding, and reasoning over marketplace policies and transaction data.
• Build autonomous resolution and decision systems that determine when issues can be resolved safely through actions such as cancellations, tracking updates, or refunds, and when to hand off to human support.
• Implement and optimize RAG, embeddings, prompt engineering, and fine-tuning for accurate, context-aware multilingual support.
• Design offline and online LLM evaluation frameworks covering policy compliance, hallucination mitigation, response safety, and containment quality.
• Deploy and serve models in low-latency, high-throughput production environments with Backend Engineering and ML Platform teams, monitoring drift and performance.
• Collaborate with Product Managers, Decision Scientists, and Customer Support Operations on automation opportunities, A/B experiments, and metrics including Automation Rate, Containment, and Chatbot CSAT.

Requirements

• Hands-on experience developing machine learning algorithms and translating research papers into clean, replicable code.
• Strong technical background and an iterative, pragmatic problem-solving approach.
• High proficiency in Python and SQL, with a focus on clean, maintainable, structured, reproducible, clear, and performant code.
• Ability to explain complex technical concepts and business implications clearly to non-data stakeholders, including why a model produced a specific score.
• Fluent written and spoken English.

Culture & Benefits

• Hybrid work model with flexibility to decide when to work from home and when to work in person.
• Up to 30 days of paid annual leave and a workation policy allowing remote work for defined periods in the EU and worldwide.
• Annual learning budget starting at €3,000 and up to 10 working days over two years for professional development.
• Share options, pension matching at 150% of the chosen contribution, supplemental private health insurance, life and disability insurance, and an Employee Assistance Program.
• Home-office equipment and a personal furniture budget of up to €540, lunch benefit, subsidised Deutschlandticket, discounted gym membership, and a dog-friendly office.
• Newest MacBook models, team-building events, and a monthly hirify.global shopping budget.