The document discusses how to build reactive microservices using a MicroProfile stack. It recommends taking a reactive and micro approach to build systems that can handle high loads and failures, provide better user experiences, and scale massively. It introduces MicroProfile as an open source specification for building reactive Java microservices and lists some of its reactive support capabilities. It also discusses adding additional reactive technologies like RxJava and React.js and demonstrates a reactive application built on these stacks with Payara Server and Micro, which support MicroProfile, Java EE, and other technologies for building reactive systems.