large file sharing

Typically I reccomend that companies levarage the platform they already have (Google Drive or Sharepoint typically). 

If you have either of those, there is a nifty feature called Files Connect you can enable. 

And usually, where appropriate, I suggest automating the creation of folders. 

For example - a folder for every Account - and a folder for every opportunity nested under the Account folder. 

Then Files Connect with automation can be used to move a file attached to a Salesforce Record directly to it's designated file folder and streamed back to Salesforce for visibility. 

There are more expensive options, but this is a functional and affordable approach.