Senior Data Scientist (m/f/d)

Your daily workout

• Model Development: You use EGYM’s diverse training and health data to build machine-learning models that support effective and healthy workouts
• Data Exploration: You analyze complex datasets, validate hypotheses, and develop new approaches for challenging problems
• LLM & Agent Design: You design and maintain LLM-based components and agents that reason over user context, call tools/APIs, and orchestrate multi-step flows to generate, adapt, and explain training plans
• LLM Evaluation: You set up robust evaluation pipelines for LLM features and agents (golden datasets, automatic metrics, human evals, regression checks, and safety/guardrail tests)
• Local & Open-Source Models: You are comfortable going beyond “just an API” - you can work with local/open-source models (running them on our infrastructure, adapting or fine-tuning them, and balancing quality, latency, and cost)
• Collaboration: You work closely with Software Engineering and Product Management while sharing feasibility insights and ongoing results
• Implementation: You develop solutions in a dynamic software environment aligned with the EGYM Tech Radar
• Innovation Monitoring: You track advancements in AI and machine learning to ensure our solutions remain state-of-the-art

Your fitness level

• Experience: You bring 5+ years of experience delivering machine-learning-based solutions, ideally in personalization, recommender systems, or decision-support products
• Programming & Data: You write production-ready Python and work confidently with structured and unstructured data across SQL and NoSQL databases; you’re comfortable collaborating with backend engineers working in Java
• ML & LLMs: You have strong ML fundamentals and hands-on experience building and evaluating LLM-powered features or agents (prompt design, retrieval, tool use, multi-step flows, defining quality criteria, building test sets, running automated and human evaluations, and doing error analysis). You’re also familiar with adapting local/open-source models and understand trade-offs in size, serving, performance, and cost
• Hybrid Approaches: You’re comfortable combining classical ML and LLMs (e.g. for scoring, ranking, recommendation, or as components in larger decision systems)
• Communication & Ownership: You explain complex topics clearly, work effectively with different stakeholders, and see problems through from definition to production launch

Your training goal for your first 6 months

• Domain Knowledge: You become highly familiar with EGYM’s health and training data
• Cross-Functional Experience: You complete a rotation in a software development team and collaborate directly with engineers
• Impact Contribution: You deliver visible product improvements and optimize your work using real usage feedback
• Process Optimization: You help us to standardize how we build and ship models and LLM agents – defining reusable evaluation suites, automating training and deployment steps, and setting up monitoring for quality, drift, and safety
• Product Partnership: You act as a sparring partner for Product Management and help extend our product vision

The equipment we provide

• Modern Culture: Be part of a modern and international company culture where talent and passion are welcomed, heard, and part of the decision-making process
• Continuous Development: Develop your skills with varied, challenging tasks and regular feedback to benefit from a steep learning curve
• Work-Life-Balance: Benefit from flexible working hours, hybrid working policy (2 office days), and 30 days of vacation per year
• Fit & Healthy: Train for free with EGYM Wellpass in several thousand sports and health facilities across Germany and/or use our in-house gym with EGYM products
• Flex Budget: Use €60 per month flexibly for public transportation and a meal subsidy
• Mentoring Program: Exchange knowledge and grow together across teams and locations through our self-organized mentoring platform
• Discounts: Get a variety of great discounted offers, from fashion to leisure, through our employee benefits portal
• Bike Leasing: Stay active and use our leasing bike offer on your way to work or in your spare time
• Subsidized Pension: Profit from our employer-subsidized pension

Contact Information