Multi-Scale computing systems aim at bringing the computing as close as possible to the data sources, to optimize both computation and networking. These systems are composed of at least three computing layers: the terminal layer, the edge layer, and the cloud layer. Enhancing the sustainability of the whole system requires a transversal approach to solving challenges such as energy efficiency or resource consumption. The offload of computing tasks between the data center, edge, and terminal, taking into account all parameters, is then the kingpin to enhance sustainability, through transversal concerns among the different scales, including parameters related to the three sustainability pillars: environment, society, and economy.