XDCR is a high-performance asynchronous data replication system used to replicate data between Couchbase clusters across different data centers, primarily for high availability, disaster recovery, and data locality. It is trusted by several Fortune 500 companies for mission-critical applications and can be tuned for optimal performance through advanced settings accessible via the Couchbase Administrator Console and supported APIs. Key tuning considerations include factors such as data nature, mutation rate, cluster workload, and network configuration, which can influence performance. Experiments conducted demonstrated how adjusting settings like Source and Target Nozzle, Batch Count, Batch Size, and Optimistic Replication Threshold can enhance throughput or conserve network bandwidth, although variations in test results may occur due to AWS cloud environment dynamics. Users are encouraged to experiment with these settings but are advised to consult with Couchbase for specialized or critical use cases, with guidance offered by Solution Engineer Nirvair Singh.