After this morning's introduction http://cseminar.web.cern.ch/cseminar/2017/0309 , Kirk Shoop, the author of rxcpp, will explain how existing data processing code and data sources can be composed with rxcpp to remove raw thread usage and express the journey from event to result more clearly in the code. Examples of using rxcpp will be shown. One example composes rxcpp with other libraries to build an application that processes tweets as they arrive. This is a workshop-style session designed for vivid discussions: please bring questions and problems.