"Now, this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning." — Winston Churchill
Updating data is usually not the end, but usually progress of a workflow. Shipping follows ordering; inventory update follows shipping; adjusting credit follows returning; The next step in the process is required to act to keep the workflow going. The workflows can be simple with few steps or complex with hundreds of steps. Business Process Management (BPM) is an industry by itself.
Couchbase 5.5 introduced Evening service. Developers can write a Javascript function to execute upon a change to the data. We refer to inserts, Updates, Merges, and Deletions together as mutations. Multiple specific use cases have been documented for developing these eventing functions.