Is it a problem if I submit my YC application in all lowercase
i know this is a stupid question and shouldn't matter but just wondering whether it would portray a careless attitude
I've zero authority or knowledge here...but my reaction to an all-lower-case resume or application would be: I don't know if they're OCD, or writing an "I did X and here's what happened" story, or what - but I won't waste any of my company's time or resources to find out.
It's probably less of a problem than submitting a YC application in all caps.
You've got exactly one chance for a first impression. If that impression looks sufficiently strange your application won't even be read but immediately discarded.
You do you, but remember that other people do, ehm, "them".