This doesn't seem to have much to do with MVC. Assuming that the beginning of the requested page can be returned while more processing is ongoing, it seems like

This doesn't seem to have much to do with MVC. Assuming that the beginning of the requested page can be returned while more processing is ongoing, it seems like a controller method would be a good place to do this. It might be interesting to try something like this with a generator, so that "for response in process_request(request): send_response_to_client(response)" would work.