Ask HN: Continuous Learning Communities?

Hello HNers! I am looking for some good learning communities. It could be a subreddit or online forum or IRC/Slack channel where the community focuses around learning technical skills.

I have been lately feeling that I want to devote more time to learning new technical skills or developing my existing technical skills more. Doing that requires putting effort on a small number of skills day after day, week after week. A community like this can provide motivation and reminder to spend time on my skill frequently enough. Any ideas or recommendations?

About what kind of technical skills? Anything is fine. Post your recommendations and links to communities and I will decide for myself what interests me. Other readers of this thread can decide for themselves if something interests them.