Key Account Marketplace Internship - Decathlon Marketplace

Join Decathlon Marketplace Belgium and discover how we bring hundreds of sport brands together on one platform to reach millions of Decathlon customers.

Do you want to see how hundreds of sports brands reach millions of customers on one platform ?

You will work with our Partner Success Managers to help our partners grow, from their first day on the platform to their international expansion.

This internship is a unique opportunity to understand the business mechanics behind a fast-growing marketplace, work with real data, and collaborate with diverse stakeholders across Europe.

As a Marketplace Intern, you’ll actively contribute to the daily management of our partner portfolio and the continuous improvement of their performance on Decathlon Marketplace.

Your responsibilities will include:

• Partner Performance Tracking: Analyze key metrics (sales, GMV, delivery quality, conversion, satisfaction) and share actionable insights with the KAM team.
• Operational Support: Help manage seller accounts via our Mirakl back office (product listings, pricing, shipping rules, content quality).
• Data Analysis: Build reports and dashboards (in Google Sheets / Excel) to monitor results, trends, and opportunities.
• Project Contribution: Support initiatives such as Showrooming (in-store marketplace visibility), Brand Deals, Duplication to other EU marketplaces, or EPR compliance.
• Cross-Team Collaboration: Work closely with logistics, content, and commercial teams to ensure the best partner and customer experience.

We are looking for a curious student who loves digital strategy and working with data.

• You are currently a student in Business, Marketing, Digital, or Data Analytics.
• You are comfortable using tools as Excel or Google Sheets (formulas and pivot tables).
• You are fluent in French and English. Knowing Dutch is a strong plus!
• You see the work that needs to be done and you are eager to learn in a fast-moving team.
• You work in a structured way and you enjoy solving problems with data.
• You are motivated by our mission and the world of sports.

• Location: You are based at our HQ in Evere (Brussels).
• Duration: You join us for a 6-month full-time internship.
• Start date: You are ready to take the field in February or March 2026.
• Flexibility: You work within a supportive team that values hybrid work and collaboration.