Writing my first code review. Even though it really is a nice review and I'm happy with the solution code, I still somehow feel like an asshole for each critique I make. Maybe it's unavoidable with code reviews / pull requests?

it is unavoidable. i think, as professional developers we shouldn't take critique personal, errors happen all the time, to everyone - i'm not always in my best mental state when i code. always be open to improve your coding style and learn from others, code reviews are a good tool for that. sometimes, a code review comment feels a bit salty or makes me feel stupid, but it's okay. xD

Teach and learn.
Reading new code can teach you how to do things, or can teach you how not to do things.
Example: jr dev write a hard to test, global state accessing function. Teach that dumbass how to write a threadsafe, easy to test function. Jr uses monads, and async await in a new unfamimilar way - learn a new thing.
It can be a very bad experience with a bad reviewer.

@magicMirror Actually I already did learn some stuff, I mentioned that as well in the review 👍