Senior Data Scientist - Rankings & Recommendations (all genders)

Munich, Germany

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Holidu is one of the world’s fastest-growing vacation rental technology companies. Our mission is to make booking and hosting holiday homes free of doubt and full of joy, by helping hosts generate more bookings with less work and helping guests find a holiday home they truly enjoy. Our team of 700 colleagues from 60+ nations shares a passion for tech, an ambition for constant improvement, and a relentless drive to bring the best experience to more than 40k vacation rental hosts and 4 million annual guests.

Your future team

Join our Business Intelligence Department, a multidisciplinary group of Data Scientists, Analysts, and Data Engineers. Together, we build ML products that directly influence GMV, conversion, and retention.

You will join a cross-functional Product team, Search Intelligence, which is responsible for optimizing ranking and recommendations for users visiting our website.
You'll be part of the broader Data Science team, which operates across cross-functional domain teams - giving you access to shared knowledge, best practices, and collaboration opportunities beyond your domain.
You’ll collaborate daily with Data Engineers, Analysts, Product Managers, and Back-end Engineers.
You’ll report to the Team Lead, Data Science.

Together, we turn data into actionable insights and innovative technology that powers how millions of guests find and book their perfect holiday home.

Our Tech Stack

Python • Airflow • dbt • AWS (SageMaker, Redshift, Athena) • MLflow

The Ranking challenge at Holidu
Holidu lists over 4 million vacation rental properties. Our ranking and personalization systems determine which of them our 70+ million annual users see, directly impacting search conversion and business results.

What's live today:

Multi-stage ranking pipeline: Reinforcement-learning-based cold ranking, contextual re-ranking, and personalized recommendations
Cold-start models for new properties with limited behavioral data
Personalized recommendations based on user browsing patterns

Some of the hard problems we're solving:

Multi-objective optimization: Balancing user relevance, conversion probability, and business value.
Personalization without history: Most users are anonymous or first-time visitors.
Cold-start: A significant share of our inventory is new each quarter. How do we surface quality properties before we have behavioral data?

Your role in this journey

You'll shape the ranking and recommendation systems that millions of guests rely on to find their holiday home. With access to extensive datasets and modern ML infrastructure, you'll work end-to-end - from identifying opportunities and prototyping new approaches to shipping models to production and measuring their impact.

Develop high-impact models and improvements for our ranking, recommendation, and personalization systems - with the freedom to explore new, creative approaches.
Take models from conception to production, continuously monitor their performance, and iterate to enhance accuracy and efficiency.
Design and run A/B tests as a core part of ranking development; success is measured by successful experiments per quarter and time-to-decision.
Collaborate closely with Product Managers and Software Engineers to identify, prioritize, and ship ranking improvements.
Ensure model reliability in production, measured by online/offline agreement, model and data drift KPIs, latency and uptime SLAs, and automated monitoring coverage.
Advance our MLOps practices with CI/CD pipelines, retraining workflows, lineage tracking, and documentation.
Demonstrate leadership in data science projects by driving technical direction, scoping initiatives, and guiding the team's prioritization and project execution.

Your backpack is filled with

4+ years of experience as a Data Scientist, with a proven track record of applying ML models to solve real business problems.
Experience working on ranking models or recommender systems is a strong advantage.
A degree in Machine Learning, Computer Science, Mathematics, Physics, or a related field.
Strong foundations in statistics, predictive modeling, and machine learning techniques, with hands-on experience using Python and SQL.
Experience with Airflow and dbt is a plus.
Solid understanding of business operations and the ability to translate data insights into clear, actionable outcomes.
A collaborative mindset and enthusiasm for using data to build world-class products that make a real impact.
AI Proficiency: You are comfortable using AI to enhance coding, planning, and monitoring. This includes successfully integrating AI tools (such as Claude code, Codex, Copilot, etc.) into your workflow and teaching others to use them efficiently.

Our adventure includes

Impact: Shape the future of travel with products used by millions of guests and thousands of hosts. At Holidu ideas become products, data drives decisions, and iteration fuels fast learning. Your work matters - and you’ll see the impact.
Learning: Grow professionally in a culture that thrives on curiosity and feedback. You’ll learn from outstanding colleagues, collaborate across disciplines, and benefit from mentorship, and personal learning budgets - with a strong focus on AI.
Great People: Join a team of smart, motivated and international colleagues who challenge and support each other. We celebrate wins and keep our culture fun, ambitious and human. Our customers are guests and hosts - people we can all relate to - making work meaningful and energizing.
Technology: Work in a modern tech environment. You’ll experience the pace of a scale-up combined with the stability of a proven business model, enabling you to build, test, and improve continuously.
Flexibility: Work a hybrid setup with 50% in-office time for collaboration, and spend up to 8 weeks a year from other inspiring locations. You’ll stay connected through regular events and meet-ups across our almost 30 offices.
Perks on Top: Of course, we also offer travel benefits, gym discounts, and other perks to keep you energized - but what truly sets us apart is the chance to grow in a dynamic industry, alongside amazing people, while having fun along the way.

Need a sneak peek?
Check out the adventure that awaits you on Instagram @lifeatholidu and dive straight into the world of Tech at Holidu for more insights!

Want to travel with us?

Apply online on our careers page! Your first travel contact will be Lucia from HR.

We are committed to diversity in all aspects of our business. We encourage applications from all genders, all corners of the world and all individual backgrounds. You are welcome to submit your application without a photo and without stating your gender, date of birth, marital status, nationality or disability status (if applicable). If you require any special assistance when arranging interviews, office visits or the recruitment process in general, please contact the relevant HR person responsible for this job and we will do our best to accommodate your needs.