Obtaining cookie profiles and valid information about daily user behaviour on the internet is equally important for websites and advertisers. In Germany, this is the responsibility of agof (Arbeitsgemeinschaft Online Forschung) with Kantar Analytics Deutschland being a key service provider. The process links cookie-based technical measurements with survey and projection data from traditional market research. This deep dive will show how such a multi-method model works in principle, how REST-APIs, SQL databases and neural networks come into play and how the models are regularly updated. The presentation will additionally describe how innovations and improvements can be implemented even during ongoing operations.