If you are looking for the Architecture of NetApp w.r.t to Hardware / Data ONTAP , then all the information is available in the Product Documentation Guides.
Good thing about NetApp unlike other Vendors is that we have a single OS Data ONTAP. So knowing how Storage Processor works / Drive connectivity / NVRAM function is all the same across different models.
If you are looking for something which is not in the public facing documents then you probably have to get in touch with a local NetApp representative.
If you are a customer/Partner who is under covered NDA then probably you might get more info.