[sdomino]

There is a really great Slack team for SEO & Marketing called Online Geniuses (https://onlinegeniuses.com/). It's not really "HN like" but it's a really great community.

[sdomino]

Just a quick note to my comment.

There are a lot of good entrepreneurial teams as well, but a lot of them have one time fees to join (part of a vetting process).

The one I mentioned above is free which is somewhat unusual for such an active community.