The text discusses how to move data from MongoDB to Couchbase using RxJava, a popular stream API. The goal is to create an Observable of Mongo Documents, transform them into Couchbase Documents, and then write them to Couchbase. This process can be easily modeled with RxJava, as demonstrated by the pseudo code provided. The author has created a Couchbase-java-importer tool that makes this process straightforward, allowing users to download and execute it with a YAML configuration file. While this is one particular way to move data between the two databases, others exist, such as CSV import and export, which can also be used with the importer. The code is simple and open-source, making it easy for developers to contribute or fork the project.