I'm humbled by the response. I was honestly afraid to open this, as I wrote this while entrenched in my emotions. I was really upset having spent a weekend on a take-home project who's feedback was basically "we're disappointed."

One of the must hurtful aspects my career was being competent enough to be left alone, hence why I never had senior mentorship. That's only partly true though, as we had a senior developer hire for myself who ended up being a total con. I don't want to go into it. I was lucky he once told me to shut up to my face so I eventually had something to go to HR with. I had to comb through code reviews, code commits, etc. and build a case have him fired. Then I was alone again.