first thank for your work, I'm interrested in your project. When I tryed to play a little with your app, I came across a minor bug:
(all of this is in my local env)
I've asked a new question and wanted to up/down vote it. When you upvote it makes +1, you upvote again it makes 0 and if you upvote again it makes -1 and freeze (you have to refresh if you want to do it again).
Try stress it a bit, does the same with down vote (in the other way) and it mess the vote system afterward.
Have a look!