Others have mentioned it incidentally, but I'll highlight it: When you're at this point, talk to them offline, either face to face, video conference, but somew

Others have mentioned it incidentally, but I'll highlight it: When you're at this point, talk to them offline, either face to face, video conference, but somewhere privately. The core message should be that the code is sufficiently convoluted that you can't effectively review it and you think there must be a better approach. Comprehensibility is always a code review concern, so you're on solid ground there. The big thing here is that there's a point where the honest code review will basically be "wow, you screwed this up big time," at which point doing it in front of other people will make things worse and not better--your coworker will probably dig in their heels and will definitely feel humiliated enough to not really be open to constructive criticism. Comes down to the whole criticize privately/praise publicly thing. It's not about politics, just human nature. And as much as people should be able to take a critical code review, taking one that effectively says you bungled the entire thing requires rather superhuman objectivity. Unlike others, I'll say that you don't have to turn this into a teaching or mentoring moment unless you're the lead and that's your job. If you want to do so, great, but that can be a lot of load to add to what should be a straightforward task. It would be good for you to be able to articulate in neutral terms some of the issues that make the code incomprehensible. You can even get a sanity check and maybe a few ideas from a trusted colleague. Your best outcome here is a followup comment from your coworker saying "after offline conversation with reinhardt, I decided to rework the code and will resubmit."