The best Slack channel is the "thanks" Slack channel. If your organization doesn't have one, set one up as a place for people to share praise and shout-outs and appreciation for big & small things
@laurahelmuth @adfinis has/had a #rants one on Mattermost, best thing as a newcomer. Positivity ia great until it becomes toxic.
@greut oh I love it. "rants" is a great idea