Data Scientist - Search Retrieval 80-100%

As the top Swiss e-commerce platform, with a crew of over 4’000 across Switzerland, Germany, and Serbia, Galaxus is poised to move into new markets. Our driving force is our determination to keep challenging the status quo. That’s why we’re on the lookout for characters who’re passionate about making genuine improvements. We’ll give you the freedom and trust to make an impact, to grow with us and to be yourself. Act galactic. Be you.

Retrieval is the foundation of every search result. As a Data Scientist on our Search team, you'll own the algorithms (keyword, vector, and beyond) that surface the right products for every customer query. Your work has a direct, measurable impact on how customers discover products and experience our shop.

Deine Aufgaben

• Design, build, and improve retrieval passes for our product search, including keyword-based (e.g., BM25) and vector-based (embedding) search
• Develop hybrid retrieval strategies that blend lexical and semantic signals, including candidate merging and score normalization
• Continuously improve retrieval systems by evaluating performance and leveraging interaction data from millions of users
• Analyze search logs and user behavior to identify recall gaps, underperforming query segments, and long-tail query issues
• Bring models from prototype to production together with engineers, ensuring low latency and high availability at e-commerce scale

Deine Fähigkeiten

• University degree in data science or a related field (MSc or PhD), as well as at least 3 years of relevant professional experience, ideally with practical experience in search or information retrieval
• Excellent Python knowledge including experience with machine learning libraries such as PyTorch, TensorFlow and scikit-learn
• Experience designing experiments and interpreting metrics for large-scale online systems (A/B testing, offline evaluation)
• Experience in handling large amounts of data, including advanced SQL knowledge and experience with database systems (e.g. BigQuery) for analyzing user interactions
• Experience in the field of MLOps, especially in the deployment and operation of machine learning models in production, e.g. with orchestration tools like Airflow or Dagster
• Solid command of English, both written and spoken; German is a plus
• Pragmatic, product-oriented mindset and good communication skills for working across disciplines
• A willingness to challenge «how things have always been done» and propose more efficient, automated or effective solutions
• Using creativity and initiative to solve problems and achieve goals

Warum startest du bei uns?

• Values, not empty words: Cooperative, innovative, piratesque, responsible, ambitious – these five values are what we practise and preach.
• Courageous thinking: We encourage everyone to think on their feet, and love it when they come up with bold or edgy ideas.
• Uncomplicated approach: Simplicity is at our core. We avoid the unnecessary and focus on what really matters – from overcoming challenges to celebrating our shared successes.
• Flexibility and freedom: We offer working-from-home options, up to 8 weeks of workation, and every position is possible with an 80% workload.
• Rapid growth: With us, growth is a continuous journey. We also support you with 2'000 EDU points per year for your professional development so there’s no risk of you getting stuck in a rut.
• Modern: With us you can work with the latest technologies every day, see our Tech-Radar.
• More than "just" work: Take part in our various employee events such as Hackathons, hiking, skiing, Böötlen on the Limmat, LAN Parties or Friday Night Drinks and, if you're interested, contribute to our Techblog.
• More benefits: 25 days of holiday, exclusive employee conditions in our online shop, mobile, internet and TV plans at company rates and many other benefits.