Hi,
I have other questions 
Is there any impact on load if the website is hosting 100 / 1000 / 10 000 producers ?
Is there any impact on load if the website is hosting 100 / 1000 / 10 000 hubs ?
Are we able to think on architecture with on one side the front end for customers, where we should be able to store on cache maximum of informations, like hubs and producers informations. And on other side, the back end part of website for hubs and producers management ? And the synchronization of the 2 parts will be done on database and file share storage.
If we are able to split the website on two parts, we should be able to better scale out and then handle the load. And then if the backend is loading too much the servers, there should not impact the front end.