Senior Data Scientist, Menu Personalization

Work with HelloFresh in Warsaw and its HelloTech organisation, HelloFresh’s global technology backbone with more than 1000 people, building the digital products that power our end-to-end food experience. From meal kits and ready-to-eat meals to specialty offerings like pet food and premium meat & seafood, HelloTech creates the platforms that bring tailored food solutions to millions of customers every month.

Our subscription-based, direct-to-consumer model relies on technology at every step, from customer-facing apps and personalization logic to pricing, forecasting, supply chain optimization, and initiatives that help reduce food waste. While our brands operate independently to serve distinct customer needs, they are united by shared platforms, data, and operational excellence built by HelloTech.

HelloTech works in autonomous, cross-functional alliances, each owning a specific product or domain end to end. By working with our Warsaw office, you will help shape scalable, data-driven products used across our markets, working with a modern tech stack and international teams to continuously improve how people discover, order, and enjoy HelloFresh’s products, today and in the future.

About the role: What's in the Box

This position is for an expert in developing and deploying large-scale recommender systems. The service provider will engage with a high-impact team of data scientists, focusing exclusively on menu personalization. As a Senior Data Scientist, the role involves a pivotal part in designing, implementing, and improving personalized recommendation algorithms for culinary products across global markets.

Expect to have a tangible impact on customer experience and business growth by ensuring customers are presented with the most relevant menu options. This involves working closely with other personalization Data Scientists, as well as Data, Backend, and Machine Learning Engineers, to deliver statistical solutions and ML models to production. Success in this role requires a curious mindset, the ability to prioritize problem statements, and the expertise to suggest multiple solutions based on potential impact. This role does not include people management responsibilities.

At HelloTech, flexibility and cross-functional collaboration are core to how we work. While this role is aligned to a specific Alliance, strong candidates may also be considered for opportunities across different teams or projects.

What you’ll do: The Recipe

• Become an integral part of a high-impact team covering menu personalization.

• Contribute to designing and implementing the next generation of recommender models, from experimentation and data collection to operationalization.

• Shape the future of customer experience by proposing new personalization approaches and evolving statistical and ML models in pace with future company strategies.

• Design and execute A/B tests to measure the impact of new recommendation strategies on key metrics.

• Work with state-of-the-art technologies like AWS (EMR, Glue, S3, etc), Kafka, PySpark, Airflow, Databricks, MLFlow, and Claude (AI).

• Collaborate closely within other functions (data engineering, backend engineering, ML engineering, product) to translate business objectives into concrete strategies.

• Analyze the performance of models to understand customer behavior and implement technical improvements.

• Contribute to a collaborative and knowledge-sharing environment, providing technical guidance and coaching to team members and stakeholders.

What you’ll bring: The Ingredients 

• Proven track record of scientific work (Bachelor's, Master's, or PhD) in computer science, statistics, physics, economics, mathematics, or data science.

• 3+ years of work experience as a data scientist focused on developing and deploying recommender systems or personalized ML models in a production environment.

• In-depth knowledge of various recommendation algorithms, evaluation metrics, and the practical challenges of maintaining a modern recommender system.

• Fluency in Python, including high familiarity with its scientific stack (Numpy, Pandas, Scikit-learn, Matplotlib). Experience in Databricks and PySpark is a plus.

• Technical proficiency in SQL for retrieving, manipulating, and analyzing large datasets.

• Experience with software development practices and tools such as Git, CI/CD, Docker, and AWS.

• Expertise in leveraging Generative AI tools (e.g., Claude, Copilot) to support model development, experimentation, and documentation.

• Exceptional communication capabilities to interact effectively with product managers, UX designers, and business stakeholders.

Above all, we are looking for individuals who will make HelloFresh better. We believe there are many different ways of developing skills and we love diverse experiences! So even if you don’t “tick all the boxes” but think you’d thrive in this role, we would really like to learn more about you.

What we offer: The Toppings

• Global collaboration at scale: Collaborate with experienced engineers and product partners across HelloTech’s international teams, in a culture of active knowledge sharing.

• Technology with real-world impact: Build and operate modern systems at global scale, supporting 6+ millions of customers and complex supply chain operations.

• Technical/Product/Design leadership: Drive best practices and influence architecture/design, quality, and ways of working in an autonomous, product-led setup.

• End-to-end development/delivery: Drive decisions from problem definition to production, improving systems and enabling long-term scalability.

• Access to workspace at Warsaw Centre Point. The hub offers modern facilities including showers, breakout zones, outdoor space, cycle parking, and refreshments (coffee, soft drinks, and fruit).

Are you the missing ingredient? If this sounds like a tasty opportunity, we’d be excited to hear from you.  We aim to review your profile and respond within 5 business days.

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