I want to build a webapp with Umbaco CMS for a user portal. I will need to make an API call to get information from CRM/Billing system and eventually would get pdf files from these systems.

What is the best way for me to store these pdf file either on webapp or preferably in CMS ? Or would need to make API calls for every pdf file request and store in cache for that session. I am concerned with the performance factor to make API call for each pdf file request.