Which event is particularly useful when aggregates depend on one another?

The "After Fetch" event is particularly useful when dealing with aggregates that depend on one another because it occurs immediately after data is retrieved from a data source but before it is rendered to the user interface. This timing allows for manipulation or the application of logic based on the retrieved data.

When aggregates are interdependent, using the "After Fetch" event facilitates scenarios where you might need to update one aggregate based on the results of another. For instance, if one aggregate's output is needed to filter or modify the results of another aggregate, handling that logic after fetching the data ensures all necessary information is available and can be processed accordingly.

This makes the "After Fetch" event ideal for orchestrating multiple queries that rely on each other’s results, ensuring that the application logic is both coherent and efficient before the data is presented to the user. It ensures that any calculations, transformations, or additional data fetching that needs the aggregated results can be properly executed without prematurely rendering the user interface, which may result in incomplete or incorrect data being displayed.