The thesis examines in detail the concept of “systemic risks” in the Digital Services Act (DSA). At the heart of the obligations for very large online platforms in the DSA are risk assessments in which only vaguely described “systemic risks” are to be assessed and mitigated by the platforms. Based on reference areas of risk regulation and social science findings, the risk management system is subjected to an in-depth analysis. The author interprets risk management system as a proceduralized concept, which is integrated into a collaborative governance of various actors. The generation of public knowledge is identified as a particular goal of these governance structures.