A framework on how to handle pull requests:
Bad naming: make sure you would understand your code if you read it a few months from now.
KISS: Keep it simple, Stupid.
DRY: Don't Repeat Yourself.
YAGNI: You aren't gonna need it: check that you are not overcomplicating something for the sake of 'making it future-proof'.
Code that is not readable: too many nested 'if's are a bad sign.
Performance issues (if that's a real concern for your application). How long does a job take?
Complicated constructions that need refactoring or comments: code should almost always be self-explanatory. Function names should ideally explain everything.
Continuous Integration errors, including tests, make sure your tests are done!
Make sure you've updated the respective stack!
Once all problems are addressed, allocate the reviewer.