To survive and assemble into multicellular organism, cells need to migrate in specific directions either in order to find nutriments or define polarity axis in biological tissues. Cellular decision-making in defining those direction relies on a complex integration of various types of signals. How cells integrate all these cues in space and time to establish and maintain polarity to perform directed migration is a fundamental but unresolved problem. Using a highly interdisciplinary approach based on our unique joint expertise in light shaping, cellular optogenetics, advanced microscopy and cell mechanics, I will discuss the strategy we developed to probe how living cells deals with signal treatment.