I thought it was "serverless"? what does "sharding" have to do with anything? I'm sorry but it seems like you throw around some vocabulary that doesn't describe your project properly, to make it look bigger than it really is. That's nice marketing but it does not feel like there is much effort put into it, when I looked at your bash script.
The idea is breakup uuid keys into
sub directories based on the first couple of letters to prevent file system performance issues. Seems like the right usage of the word from a dictionary perspective.