I would like to announce that we have started using Github Discussions for most of the technical discussions in Autoware development.
We will still be using Discourse for any topics that worth attention from wider community, but topics that are specific to Autoware including questions, unconfirmed bugs, feature request, design discussions, etc, I recommend to create a thread in the Discussions rather than in Discourse where we have more watch from Autoware core developers.
For the use of other communication tools, please refer to Support Guidelines in Autoware Documentation page.