As we have learned from the previous example, Reactive Streams drastically increases the composability of reactive libraries. We have also learned that the most useful way to verify the compatibility of the Publisher is just to apply Technology Compatibility Test Kits, which are provided with the Reactive Streams specification.

At the same time, the specification brings a pull-push communication model for Reactive Streams. This addition solves the backpressure controlling problem and at the same time reinforces communication flexibility by offering a choice of which model to use.

After the Reactive Streams Specification was included in JDK9, its significance skyrocketed. However, as we learned, this improvement brought some overheads in the need for type conversion between two variants of the specification.

As we understood from the previous...