For example, I do this with my website. I receive comments via email (with the sender’s addresses hashed). Each page/comment-list/comment has its own rss feed that people can “subscribe” to. This allows you to get notified when someone responds to a comment you left, or comments on a page. But all notifications are opt-in and require no login because your rss reader is fetching the updates.
Since I’m the moderator of my site, I subscribe to the “all-comments” feed and get notified upon every submission. I then go review the comment and then the site rebuilds. There’s no logins or sign ups. Commenting is just pushing and notifications just pulling.
example https://spenc.es/updates/posts/4513EBDF/
I plan on open sourcing the commenting aspect of this (it’s called https://r3ply.com) so this doesn’t have to be reinvented for each website, but comments are just one part of the whole system:
The web is the platform. RSS provides notifications (pull). Emailing provides a way to post (push) - and moderate - content. Links are for sharing and are always static (never change or break).
The one missing thing is like a “pending comments” cache, for when you occasionally get HN like traffic and need comments to be temporarily displayed immediately. I’m building this now but it’s really optional and would be the only thing in this system that even requires JS or SSR.