After completing his studies (ENSAM & MBA IAE), Guillaume built his entire career in the industrial sector, focusing on Supply Chain and Operations, working with major corporations such as Unilever and Veepee.

It was during his time at the e-commerce company that he identified a major issue: the lack of solutions for reusing defective, and therefore unsellable, product returns. The absence of an industrial player dedicated to product revalorization was a turning point, leading him to create Reekom, a profitable industrial company helping brands and retailers engage in product reuse.