Contemporary European cities have become so large and complex that is extremely difficult, especially in times of economic crisis, to set up for them a top-down type of project. Cities can respond in a more measured way to the inevitable ongoing change by continuously mutating, in a process of collective awareness about their real-time status. This position was built up through a plethora of bottom-up, shared actions that are co-designed and implemented, and belong to a process that encompasses also what is transient and temporary, what is ad-hoc and what relates to the digital sphere. Faced with this challenging backdrop, the subject matter of design comes into play and, by operating on services, events and analogical and digital communications, it sets itself up as a discipline that can mediate between the need to govern continuous urban mutation and the way in which this proposal can take an effective and appropriate shape. In this article, the authors take stock of the role of design within the processes of mutation that are occurring within several large urban areas in Italy, in the cities where a culture of design is prevailing over grand projects of modern-day “urban mysticism”. This study will closely examine the class of events that form a process rather than a product. As such, they can adapt easily to a logic of continuous mutation that is feather-light, sustainable and engenders participation, both when design is their pretext and when design is the instrument to give events substance and a tangible form