We do have quite a few notifications systems on Steem: built by general-purpose interfaces, on discord (GINAbot), on mobile (Steemify, eSteem, Partiko).
Steemit.com doesn't have a notification system, but the beta site does, probably relying on the hivemind code, so we will likely see it on the main site with the communities.
The question is, if now someone wants to be notified of the posts being published in a community, what do they do? In this case I mean notifications that beep, ding, flash or whatever. Not the silent, unobtrusive ones, to be consulted at a later time.
Such a feature may be useful for moderators in not very active communities. Or even subscribers to small not highly active communities.
There is at least one way to get notified instantly about new posts published in a community. But it isn't a feature of the Hivemind communities. Not even sure if it should be, or if this should be left in the care of third party services, if they can handle it.
Here's how you can receive instant notifications about new posts in a community: using GINAbot. May not be the only way, but that's one way I know.
I won't give you advice about how to set up your GINAbot notifications on Discord, if you don't have them yet for your account, but you can easily find how if you visit /@ginabot account.
Then things are pretty straightforward.
You tell GINAbot to remind you which is the stats page for your account, by writing this line to @ GINAbot on discord:
..set (no spaces, just enter, if you only have one account set up for GINAbot)
..set YourSteemAccountName (if you have multiple accounts set up for GINAbot)
GINA replies with the link to your settings page.
On the settings page, assuming you enabled notifications, if you go down the page, you'll see something like this:
Or with some added tags, in which case, you probably already know how it works.
Let's say you want to be notified of the posts published in this community, "Communities Feedback". It's unique hive id is "hive-144703". You can take it from here:
With that hive id copied, which is also a tag on Steem, you go to the settings page we opened above for GINAbot, click Add (1), and in the new field which is added, you paste your community tag (2). Like in this screenshot:
Then you click Save Changes button at the bottom of the page.
You can of course do the same with any community. And you can add multiple communities (i.e. multiple community tags). Or remove the ones you don't want by clicking the red "del" and then save changes.
I know I received this question at least once. But as the conversation went then, we need to make the process much easier for the larger Steem user base and the newcomers. The foundation has been laid by introducing a notification system where previously there was none in beta.