In migration studies, there is an increasing interest in understanding how migration processes are shaped by different forms of brokerage and mediation. We relate these debates to the everyday struggles of migrants in the city of Athens. In so doing, we propose a shift from the all-encompassing view on infrastructures, that is, as systematic entities of facilitation/control to the infrastructuring practices of migrants. This implies a focus on how migrants create dynamic social platforms, and how these platforms relate to formal infrastructures and industries. We analyse these infrastructuring practices through a conceptual lens of resonance that is sensitive to the constitutive (how things, people and processes are brought together) as well as travelling capacities of these practices (how the platforms shift to other places). With an ethnographic approach, we create in-depth insights into the ways in which migrants mediate im/mobility in the urban environment of Athens through infrastructuring practices. The paper concludes by reflecting on the promises and limitations of the infrastructuring practices as sites of solidarity. We thereby argue that there are many links to make within the mobile commons debate. At the same time, our findings highlight that the transformative potential of infrastructuring practices does not always go along with a clear claim on solidarity.