In our digital and interconnected world we constantly leave digital traces logging our daily activities such as the movies we watch, the route we follow on our daily commute, the friendships we have in the online social network, and so on. Despite this wealth of data we still lack a solid theoretical ground and a comprehensive modelling framework to characterize the mechanisms shaping the evolution of the socio-technical systems surrounding us. My research work is to unveil and describe these underlying processes by using Complex Systems techniques in combination with machine learning tools. The results are interesting not only from a theoretical point of view but can also provide valuable decision support tools to understand, control and dynamically forecast the sustainability of such systems. I am also engaged in the development of digital platforms for sustainability to create playful environments aimed at assessing the present situation and allow citizens to participate in the decision process to conceive and simulate future scenarios.