Unless you use https://www.hnreplies.com/ https://www.hnreplies.com/, you don't get a notification for when someone has replied to your comment. Even then it is

Unless you use https://www.hnreplies.com/ https://www.hnreplies.com/, you don't get a notification for when someone has replied to your comment. Even then it is as an email, decreasing immediacy and causing back and forth sessions to have overhead. I understand this as an intentional feature of HN.