The blog post explores the inner workings of the Couchbase Eventing Service, focusing on how mutations are processed by Eventing Workers and the vBucket-to-worker assignments. It describes how Couchbase shards data into 1024 vBuckets, which are distributed across nodes, and how workers are tasked with processing a subset of these vBuckets. The document explains that mutations are not processed sequentially due to concurrent operations on different vBuckets by various workers. When load increases, Couchbase can seamlessly rebalance the cluster by adding more Eventing nodes, redistributing vBuckets without losing mutations, thereby providing elastic scalability. Additionally, the text discusses the use of an online real-time debugger for debugging code, warning against its use in production environments due to potential timing issues and out-of-sequence mutation processing. Overall, the post aims to deepen understanding of worker ordering semantics and the operational dynamics of the Couchbase Eventing Service.