This talk was recorded at Scala Days New York, 2016. Follow along on Twitter @scaladays and on the website for more information http://scaladays.org/. Abstract: A reactive application doesn't live in isolation, it has to connect with the other components, and try to keep the whole system reactive. Spark, as an element of a Fast Data architecture, is one of these components to connect to. With the addition of the back pressure support to Spark Streaming in Spark 1.5, and the other characteristics of Spark, it is simpler than before to fully integrate it in a reactive system. This talk with describe the streaming model in Spark, its support of back pressure, and show, in a demo, how to use Reactive Streams to integrate Spark Streaming and a reactive application in a reactive system.