Since our company is so small (< 10 engineers), we do code reviews across platforms – so I review iOS and web code even though I’m an Android engineer.
I haven’t gotten any negative feedback on my code review yet, but I want to make sure I’m doing it properly. How can I suggest improvements on other engineer’s code, even if they’re on a different platform, or if they’re more senior than me?
First thing's first: The entire point of code review is to try to level up the code quality, either directly (e.g. "We can write this method in this better way.") or indirectly (e.g. "I think we can establish this best practice on the team to improve future code quality."). So don't feel bad about pointing out that you think a peer's code can be better in core review - That's the entire point!
The main things around leaving code review feedback is to be kind and empathetic. Use tentative language always and criticize the code, not the person. You're probably already doing that, since you haven't gotten any negative feedback on your code review so far.
For folks who haven't seen it yet, here's the in-depth session we did about code review best practices.