I mean, I could write a server that redirects the notifications pushed to me and read the actual posts on the instances themselves

Yes, I now understand I need to have a server listening for the notifications being pushed to me

I’m a web developer, so…

Who or what is going to send this request if not some server that implements ActivityPub?

Me, directly

ActivityPub works via pushes. So there’s nothing to query. There HAS to be some server for it to send and store that data.

Great, this is what I wanted to find out, so there has to be something listening for pushes

There has to be a service running behind that domain name to do something.

To do what, exactly?

Let’s say I just sent a request from my non-existent server with my user id, and just every time I wanted to check whether I got replies I would query the other server (which a Lemmy server would do to get notifications about replies or upvotes)

If I subscribe to !asklemmy@lemmy.ml I could just… check !asklemmy@lemmy.ml without actually loading any data to a server, I could just literally load it from lemmy.ml

I COULD host an instance, but why bother to store that data if I’m only going to be using it myself?

Why does there have to be an instance there? Who checks that?

I joined two of them and they both went down