https://groups.google.com/forum/#!forum/modin-dev
General questions, potential contributors, and ideas should be directed to the developer mailing list. It is an open Google Group, so feel free to join anytime! If you are unsure about where to ask or post something, the mailing list is a good place to ask as well.
https://github.com/modin-project/modin/issues
Bug reports and feature requests should be directed to the issues page of the Modin GitHub repo.