Is there anything like StackOverflow but for code reviews?

If you show your code to unlimited public, there is plenty of sites for this like GitHub or Bitbucket, but itʼs your problem to attract enough reviewers (both in quantity and quality) to attend your project. You donʼt directly need an open license for this publication type, but interest to your project would be otherwise utterly weak.

If you donʼt show your code, this falls back to the trivial case of proprietary resource.

So I donʼt understand the very idea of the question unless it is rechecked or extended.

Some programmer forums allow posting code to discuss any aspect of it, I participate in a few. But in that case you wonʼt be able to control discussion, and you have to find out how to make your request interesting.

Code Review Stack Exchange, you might have missed it from the confusing sea of pages they offer:

https://codereview.stackexchange.com/

Why do you want others to do a code review? Why not keep it within your team?