Data is considered one of the most important strategic resources in the financial sector. However, it is only with a clear data architecture and a robust infrastructure that it can become a reliable basis for decision-making. The fundamental question is therefore: How can companies create the conditions necessary to make data in the financial sector systematically, consistently, and effectively usable? The focus is on the central building blocks of a sustainable data management approach – from the integration of different data sources to governance and clear responsibilities to ensuring data quality and transparency. It is about moving from fragmented information to a common "single source of truth" that enables informed decisions at the top management level. The discussion explains why data management is not an IT project and what course must be set today to ensure that data-driven decisions in the financial sector become a sustainable and effective reality.