The Doctoral Thesis explores Sustainability-oriented transition mechanisms (SUS) at different levels of analysis (Country, inter-organizational, and organizational levels). The focus of the study is Digital Transformation (DT) and the Collaborative (multi-stakeholder) (COL) dimensions. By disentangling between COL and DT, the thesis proves that Digital Transformation and the Collaborative dimension are sufficient conditions to achieve Sustainable outcomes. In particular, the Collaborative dimension mediates the impact that Digital Transformation has on Sustainability transitions, which the existing literature identifies as a direct effect. The motivation behind these results seems to emerge from the explorative longitudinal case study, where a digital platform represents a tool able to increase the efficiency of collaboration dynamics and enable sustainable outcomes. After five years, the platform ecosystem collapsed as the leading ecosystem firm failed to effectively engage with multiple stakeholders toward sustainability outcomes and began transitioning towards lower levels of sustainability.