Optimization is coming back as a major developing research area in economics. There are at least two reasons for this. The first one is the emergence of online platforms, which act as central planners and need to solve complex optimization problems such as matching service providers with customers, introducing potential dating partners, performing dynamic pricing tasks, etc. The second reason is that econometric methods have been cross-fertilized by novel techniques from machine learning, that heavily rely on optimization tools. This conference is a chance for experts on optimization, machine learning, and economics to meet and discuss the current frontier of the scientific knowledge at these intersections.