Self-service data preparation is becoming ever more important for data scientists – experts and Citizen Data Scientists alike - especially when focusing on extracting business value out of Big Data. Data preparation is a crucial and often time consuming phase required to pre–process information used to generate reports and train Machine Learning algorithms. In this talk we will discuss some techniques (Data Lake Dictionary, Join Recommender, etc.) that can be used as powerful tools for quickly and efficiently preparing the huge amounts of data stored in Data Lakes.