Senior Data Scientist (f/m/d) at JustDice GmbH

Hamburg, Germany

on-site · full_time · Visa sponsorship

Responsibilities:
- Design and improve large-scale targeting and recommendation models used in real-time bidding.
- Develop and refine bidding policies using Bayesian methods, reinforcement learning and other optimization approaches.
- Implement meta-learning and personalization systems to improve relevance across changing contexts.
- Plan and execute rigorous A/B tests and analyze results to inform product and policy changes.
- Ship production-ready models and infrastructure integrations (Python, Kubernetes, AWS, Airflow, MLFlow, Trino), and monitor model health.
- Mentor teammates, document designs and participate in architecture discussions to raise team capability.

Requirements:
- 4+ years of professional Data Science experience, ideally in AdTech, mobile gaming, e-commerce or related domains.
- Hands-on experience building and deploying recommender systems and neural network models at scale.
- Strong foundation in Bayesian methods, RL, experimentation and causal analysis.
- Proficiency in Python and SQL; familiarity with Kubernetes, AWS, Airflow, MLFlow and Trino.
- Experience operating models in real-time or low-latency environments and translating metrics into business impact.
- Collaborative mindset, clear communicator and ability to take ownership end-to-end.