Apache Spark provides a powerful solution for transforming data within Couchbase, particularly when migrating from more rigid database structures. By leveraging Spark's integration with Couchbase's various interfaces, such as the K-V interface and the DCP streaming interface, developers can efficiently manage data transformations. An example scenario involves converting JSON data profiles from a partner for a game launch, requiring a one-time transformation that includes a lookup from a MySQL database. Spark allows for the streaming and transformation of data, with the ability to enrich JSON documents with additional information from MySQL, and then re-store the transformed data back into Couchbase. Despite some challenges, like managing large MySQL datasets or the experimental status of Couchbase's DCP interface, Spark's framework offers scalability and potential for more complex transformations, as well as enhancements like machine learning models. The described methods, while straightforward, provide a foundational approach to handling data transformations and migrations in modern data environments.