Mario, a famous munich pizza baker, has an online shop based on MongoDB. Marios current goal is to increase his cross- and up selling rate. He hired a statistician and built an online recommendation engine with MongoDB. This talk will show how to build an online recommendation engine based on MongoDB and Apache Mahout. Therefore we will show which recommenders must be built to increase the cross- and up selling rate and how his recommenders can be integrated in Mario's shop infrastructure. Finally a realtime dashboard will be shown to verify the effectiveness of recommenders.