University of Amsterdam is seeking four PhD candidates and one postdoctoral researcher for the recently established Mercury Machine Learning Lab (MMLL). In this lab, researchers from the University of Amsterdam (UvA) and Delft University of Technology (TU Delft) will be working together with data scientists from Booking.com to develop the machine learning foundations for a new generation of recommendation systems. Motivated by real-world problems faced in industry, we will investigate fundamental problems regarding generalization and bias removal in data analysis.