For the last two years, CESSDA has been leveraging DDI Profiles to improve the quality and alignment of metadata harvested from multiple service providers across Europe. These profiles are now deployed in production and are used to support multiple applications like the CESSDA Data Catalogue (CDC) and the European Question Bank (EQB). The profiles also span multiple flavours of DDI including 1.2, 2.5, 2.6, 3.2 and 3.3. This presentation firstly gives simple explanation of where DDI profiles add value to XSD schema; secondly it gives an account of how DDI profiles have been developed, published and incrementally improved over the last two years by CESSDA Metadata Office (MDO), as well as an insight into what architectural components are required to fully implement the profiles in real-world infrastructure e.g. the CESSDA Metadata Validator (CMV). Lastly, based on lessons from the field, we present a critique of the current semantics of DDI Profiles and offer suggestions for additional features in the next iteration of DDI Lifecycle, to increase the semantic expressivity of profiles, as well as including better hooks for documentation and annotations.