This article looks at the differentiated inner workings of professional mobility among workers in logistical warehouses, a sector of activity that crystalizes the effects of policies advocating the flexibilization of the labour market. On the basis of an ethnographic survey carried out in Seine-et-Marne, it focuses primarily on the study of entry mobility in warehouses, and shows that interim employment is at the root of social diversification in workers’ profiles. Repeated mobility between warehouses allows us to observe the constraints and the resources mobilised by interim employees in order to cope with the precarity of their conditions of employment. Finally, the analysis reveals the various types of job retention, between fragile professional advancement and forced stabilization, within the warehouse context.