I kinda don't want to run my own server for this. If I was going to do that, I'd probably just write small server with Express that stores the blobs in memory. It's less than 1GB total data.

(And if I was going to use a datastore, I'd probably use CouchDB. My frontend already uses PouchDB to cache content on the client side.) 

 Just dont put 100k files in a directory ;) 

 Haha, yes of course. I'm going three deep on the directory structure.  E.g. file "abcdef..." lives at "a/b/c/abcdef..."