This presentation will be a lively discussion with hands-on coding to illustrate how to construct a reactive, event-driven data flow pipeline. We will use multiple library implementations of the Reactive Streams specification, such as Akka Streams, Eclipse Vert.x and RxJava. The sample use case will mimic a real-life example of data being collected from multiple distributed sources, which will then be fed to a legacy processor as «wrapped» by a reactive microservice. The resulting data will flow to a «sink» to be prepared for further processing. We will highlight the strength of the Reactive Streams in controlling backpressure during processing.