REWE Group Data Scientist interview questions & guide 2026

Our interview process is designed to evaluate both your technical rigor and your ability to apply data science to real-world retail problems. The following questions reflect the patterns observed in our interview loops.

SQL and Data Manipulation

These questions test your ability to handle large datasets efficiently. Expect to demonstrate your proficiency with complex queries.

• Write a query using SQL window functions to calculate a rolling average of product sales over the last 30 days.
• How would you handle missing values or data quality issues in a large transaction dataset?

Preparation should focus on demonstrating both depth of knowledge and a pragmatic mindset. REWE Group interviewers value candidates who can connect their technical expertise to the specific challenges of a large retail organization.

Role-related knowledge – You must be comfortable with the end-to-end data science lifecycle, from data extraction to model deployment. Be prepared to discuss the practical trade-offs of different algorithms, especially in production environments.

Problem-solving ability – We look for candidates who can structure ambiguous problems. When faced with a case study, articulate your assumptions clearly and define your metrics before diving into the solution.

Leadership and Communication – You will often work with cross-functional teams. Demonstrating that you can influence stakeholders through data-driven insights is as important as your technical output.

Cultural Alignment – We value curiosity and a collaborative spirit. Be ready to discuss your motivation for joining REWE Group and how you approach professional growth within a large, established organization.

The interview journey at REWE Group is designed to provide you with a comprehensive understanding of our team culture while allowing us to assess your fit for our specific analytical challenges. Typically, the process begins with a recruiter screen, followed by one or more technical or case-study-focused interviews with team leads and senior data scientists.

You should expect a process that emphasizes your professional experience and your ability to apply methodology to real-world scenarios. We value transparency; you will have opportunities to ask questions about our current technical stack, the challenges we face, and how our teams collaborate. Our goal is to ensure that both you and our team feel confident about the potential for a successful, long-term partnership.

The visual timeline above provides a high-level view of our standard recruitment flow, ranging from initial screenings to final discussions. Use this to pace your preparation, ensuring you have enough time to brush up on both technical fundamentals and your own project history. Note that while the core structure remains consistent, specific teams may adjust the focus of the technical rounds based on the current priorities of their department.

Technical Rigor and Methodology

We evaluate your depth of understanding in statistics and machine learning. A strong candidate doesn't just know how to run a model; they understand the underlying assumptions and limitations.

Be ready to go over:

• Statistical significance and p-values in the context of A/B testing.
• Model deployment strategies for gradient-boosted models.

As a Data Scientist, your primary responsibility is to transform raw data into actionable insights that move the needle for REWE Group. You will be expected to:

• Design, execute, and analyze A/B tests to optimize digital and physical retail experiences.
• Develop and deploy machine learning models that address real-world problems such as demand forecasting, customer churn, or personalized recommendations.
• Collaborate closely with product managers and engineers to ensure that models are not only accurate but also scalable and maintainable.
• Communicate complex findings to stakeholders, helping them understand how data informs strategic decisions.
• Maintain a focus on continuous improvement, questioning existing processes to ensure our analytics remain at the state of the art.

We are looking for candidates who combine technical proficiency with a business-first mindset.

• Must-have skills: Proficient in SQL (including window functions), strong experience with A/B testing design and analysis, and a solid foundation in machine learning deployment.
• Nice-to-have skills: Experience with cloud-based data infrastructure, familiarity with retail-specific domain problems, and a track record of mentoring junior team members.
• Soft skills: Excellent stakeholder management, the ability to communicate technical trade-offs, and a proactive approach to solving ambiguous, high-impact business problems.

Q: How long does the interview process typically take? A: From the initial application to a final decision, the process generally spans a few weeks. We aim to keep communication timely and transparent at every stage.

Q: Are there technical assessments or coding tests? A: We focus more on case studies and discussions about your past projects rather than abstract coding tests. You should be prepared to talk in detail about the methodology and challenges of your previous work.

Q: What is the team culture like at REWE Group? A: We value collaboration and intellectual curiosity. Our teams are increasingly focused on scaling our analytics capabilities, and we look for people who are excited to contribute to that growth.

Q: How much weight is placed on my past projects? A: Quite a lot. Your ability to explain the "why" behind your methodological choices in past projects is a strong indicator of how you will approach problems here.

• Own your narrative: Be prepared to walk through your resume, specifically highlighting the technical challenges you faced in previous projects.
• Understand the business: Research how REWE Group operates. Being able to frame your technical answers within the context of retail will set you apart.
• Ask meaningful questions: Use your time at the end of the interview to ask about the team’s current technical hurdles or how they measure success.
• Be clear on methodology: When asked about a model or an experiment, explain your choices. We are interested in how you think, not just the tools you use.

Joining REWE Group as a Data Scientist offers a unique opportunity to apply advanced analytics to one of the most dynamic retail environments in the world. By focusing your preparation on the core areas of A/B testing, SQL manipulation, and product-sense, you will be well-positioned to demonstrate your value to our team. Remember that we are looking for partners who are as interested in the business impact of their work as they are in the technical implementation.

You can explore additional interview insights, practice questions, and preparation resources on Dataford to further sharpen your skills. We encourage you to approach your interviews with confidence and a clear focus on the value you bring to the table.

The provided salary module reflects the expected compensation range for this role, accounting for variations in seniority and experience. Candidates should use this as a benchmark for their own expectations during the negotiation process, keeping in mind that total compensation may include additional benefits and bonuses unique to REWE Group.