Indeed the server logic used to perform the actual grouping or any other server operations like filtering or sorting is considered a developer effort. The required Grid data operations can be applied to the data on the server using any custom approach. The data operations should be performed according to the current Grid State which holds information about the applied paging, grouping, soring and filtering.
If you are using ASP.NET Core or ASP.NET MVC then you can rely on the DataSourceRequest model binder and the ToDataSourceResult() method which process bulk data operations on the server:
In case further information is required for this case, please provide some more relevant details about the specific use - case scenario so that I can better understand the issue which you are facing. Thank you.