Couchbase's Database Change Protocol (DCP) allows the database to "rewind history" and replay all changes that have occurred since its inception, enabling it to resolve any internal state. This superpower can be exploited to do extra cool stuff with documents, such as replicating data to completely different databases, using queue-based approaches, and integrating with other microservices. DCP can also be used for time series/revision analysis, treating every item as a time series, which enables entire families of interesting downstream data analytics. The protocol is built into the core of Couchbase's storage architecture and provides a basis for features like cross-datacenter replication (XDCR). A DCP client can be written to accept DCP messages and process them, allowing developers to tap into this stream of events and perform various operations such as notifying marketing teams when a beer hits 5 stars. However, it's essential to consider gotchas like filtering based on keys, handling single points in time, and flow control techniques. With DCP, Couchbase becomes easier and more flexible to integrate with other systems, enabling developers to build powerful downstream tools and unlock new analytics capabilities.