The Economist: Build-A-Voter Tool
Not explicitly related to FiveThirtyEight, but I think this sub will have a lot of fun with this so I hope the mods don’t mind.
Basically you can plug in a set of voter characteristics and it will show you how likely that “person” is to vote for each candidate and how they compare to other cohorts.
Apparently, I have an 82% chance to vote for Harris.