Junior Data Engineer R&D

The Data Platform team is looking for an intern Data Engineer based in Lille.

At Decathlon, our Data teams drive a powerful technological and organizational transformation to support over 1,800 stores and 100,000+ employees worldwide. Decathlon Digital is the technological powerhouse driving this change, acting as an internal tech lab where custom, game-changing solutions are born.

Within the Data Platform, our priority is to simplify and drive Decathlon's data-centric transformation. We manage massive data infrastructures for a community of 170+ million customers, ensuring smart decisions are made across every activity—from fabric choices to production forecasts. You will join the team responsible for building Decathlon's central Data Lake, our single source of truth.

YOUR MISSION

Our Data Lake transforms data through progressive layers to power everything from interactive dashboards to advanced Machine Learning (product recommendations, demand forecasting). As we stack these transformations, manually tracing the origin of data becomes unmanageable.

The core of your internship is to design and implement an automated tracking solution using (Fine-Grained) Data Provenance.

In collaboration with academic experts Pierre Senellart (ENS, PSL University) and Silviu Maniu (Professor, University Grenoble Alpes), as well as our engineering teams, you will be expected to:

• Contribute to the design and implementation of a Data Provenance tool compatible with Apache Spark.
• Bridge the gap between theoretical research and industrial reality, exploring algorithmic approaches for massive data scale.
• Ensure Trust & Reliability by guaranteeing the accuracy of results for data consumers and enabling precise Root Cause Analysis.
• Solve compliance & testing challenges, ensuring PII data is tracked for GDPR and extracting representative subsets for prototyping.
• Lead Knowledge Transfer by translating advanced theoretical concepts into accessible insights to upskill the wider Data Engineering team.

TECHNICAL STACK & ENVIRONMENT

• Good knowledge of SQL, familiarity with relational algebra is a plus
• Good knowledge of Python, Scala is a plus
• Git
• Understanding of distributed systems and parallel processing. 
• Experience with Big Data technologies (e.g., Apache Spark, Hadoop, Hive, Delta Lake) is a plus.

WHAT YOU BRING

• Education: Master 1 or Master 2 Student in Computer Science, Data Science, or Applied Mathematics.
• Problem Solver: You genuinely enjoy tackling challenging algorithmic problems and complex coding puzzles.
• Research Oriented: You are comfortable reading research papers and exercising critical thinking to adapt theoretical models to specific project needs.
• Software Craftsmanship: You strive for clean, maintainable code and are eager to apply engineering best practices.
• Curious & Humble: You are open-minded, ready to question your own assumptions, and enjoy brainstorming with diverse stakeholders.
• Languages: You are fluent in both French and English, allowing you to collaborate effectively within our international teams.

WHY JOIN US?

• Sport & Community: You will work in a vibrant workplace that encourages sports practice and team-building moments with your fellow teammates.
• Brand Ambassador: You will have the chance to test new Decathlon products and share your passion on the field by joining our internal sports clubs.
• Join a supportive community of interns and apprentice students: collaboration, conviviality, and dedicated events.
• Learning Culture: You are joining a Happy Trainees 2025 certified company, recognized for providing a high-quality learning environment for interns.
• Work Tools: Choice of hardware (Mac or Windows) provided in line with your missions and our social responsibility commitments.
• Commuting: 50% reimbursement of your public transportation pass.

DECATHLON DIGITAL CONTEXT 

What if technology allowed us to push the boundaries and take sports experiences to new levels? That's exactly our goal at Decathlon Digital We are a team of 5,000+ experts in software engineering, product management, data, cloud, and cybersecurity, distributed across Paris, Lille, and Amsterdam. Together, we are creating the largest digital sports platform, leveraging tech innovation from design to value chain optimization, connected experiences and product second life.

Changing the game for good. We are in this for the love of sports. And like everything we love, we want it to last. That's why we are embarking on a journey to create a more sustainable tech model, reducing our direct environmental impact while maintaining a safe, diverse, and inclusive space for all our people to learn and thrive together. Team up with us to design the digital future of sports.

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