The sizes of living organisms span over twenty orders of magnitude or so. Mechanistically, the control of organ and organismal size results from the complex integration of autonomous programs, whereby intrinsic signals specify organ identity, patterning and growth properties, and systemic controls adjust organ growth to developmental and environmental cues. Over the last 25 years, a growing number of laboratories including ours have tackled several aspects of growth regulation in the Drosophila model. Our work focused on specific communications between organs allowing integrating environmental cues like nutrition into growth control, but also setting up body proportions. These organ cross-talks are mediated by numerous diffusible signals including conserved hormones. I will present some of our recent work exploring both global and local mechanisms of growth, as well as the robustness of these controls.