How do you know when someone replies to your comment?

There aren't any automatic notifications and that's by intentional design, to break the strong engagement loops that other social media sites run on.

Confirmed by HN's @dang here:

https://news.ycombinator.com/item?id=22930391

(You can *manually* scan for replies in your "threads" link, on the off chance you haven't noticed that).

https://www.hnreplies.com/

I check when I notice my points have gone up, and I'm curious what it was. Sometimes that means it'll take a few days before I've even noticed.

As someone else pointed out, it's by design. Twitter and YouTube sometimes get bogged down by inevitable debates. It's avoided here.

Checking the "threads" page. A notification on the main page would be nice (maybe in place of the useless and attention-hostile points counter?).