The messaging flow components are critical to design any business flow. This chapter discussed such components in detail. The Filters are the endpoints that allow or disallow messages based on a set of predefined criteria. Routers mainly distribute the messages based on a routing algorithm. The rest of the chapter described another set of flow components consisting of Splitters, Aggregators, and Resequencers. Splitters mainly slice the message stream into smaller pieces, while the Aggregators reassemble them back into the original message. The Resequencer waits for a set of messages to arrive and, if necessary, reorders them before they are reassembled.