With the European Strategy for Data, launched in 2020, the Commission has envisioned the EU as a leader in a data-driven society, where important societal benefits can be achieved by ‘unleashing the data’. The aim is to create a single market for data, allowing data to flow freely within the EU and across sectors, for the benefit of businesses, researchers and public administrations. European and national administrative authorities play a central role in achieving these goals. Building on the GDPR, several new acts regulating the data-driven society and AI continues to shape a European composite administration for data based on the cooperation of European and national public authorities. The executive strategy of the composite administration combines a compliance-based approach, guidance and capacity building, with strong deterrents, high administrative fines. This developing composite administration can be expected to have important influences on core areas of democratic policymaking, including collecting and making accessible information and personal data, defining prerequisites for research and technical development. Focusing on the GDPR, the AI Act and the European Heath Data Space Regulation, this chapter investigates whether the European composite administration for data is adequately construed to respond to the constitutional requirements of the representative democracies of the EU and its Member States. More concretely, how can the European composite administration fulfil the two basic tasks of the executive under the rule of law, to ensure that the aims and contents of the legislation are realised and that constitutional restraints of public powers are upheld? The conclusions drawn are that the constitutional setting of the composite administration and the allocation of tasks and competences in institutional and procedural responsibilities remain underdeveloped. It is therefore difficult to foresee how this administrative organisational model can uphold the requirements stemming the rule of law, to ensure that the law is applied efficiently and that public power is limited, predictable and performed in accordance with the law.