The Rails team has decided to migrate all the talk, docs and core Google groups to https://discuss.rubyonrails.org/.
Starting from now can you post any core discussion there. If you are having any trouble finding your bearings I will be watching closely and do my best to help out!
The theme used on the forum is open source and accepts contributions https://github.com/rails/discourse-rubyonrails-theme
See you on the forum! We will be locking this group shortly and migrating the final missing posts over to the new home.