Integrating survey microdata with auxiliary sources—such as administrative records, metadata, and paradata—significantly enhances the analytical potential of quantitative social science research. This article examines the methodological frameworks of three major international surveys: the EU Gender-Based Violence (EU-GBV) survey, the European Social Survey (ESS), and the Programme for the International Assessment of Adult Competencies (PIAAC). By analyzing their approaches to data collection, management, dissemination and integration, we explore how microdata, paradata, metadata, and administrative records are structured, utilized, and aligned with the principles of FAIR (Findable, Accessible, Interoperable, and Reusable) and Open Data. Our comparative analysis highlights key differences in data accessibility, interoperability, and technological infrastructure, reflecting variations in methodological design and institutional priorities. Metadata emerges as a crucial element for ensuring data transparency, documentation, and reusability, while paradata plays a vital role in monitoring microdata quality and optimizing fieldwork procedures. Administrative data, in turn, provide valuable macro-level insights that support multi-level analyses and a more comprehensive understanding of complex social phenomena. Furthermore, we discuss the role of research infrastructures and international organizations in fostering standardized frameworks for data integration. By synthesizing these insights, this study contributes to ongoing discussions on best practices for managing and integrating complex datasets in social science research. Ultimately, we argue that strengthening these integration efforts can enhance the comparability, transparency, and efficiency of international survey methodologies.