I am with a web application developed almost entirely with Java in the back and Angular in the front, using Web Services .
One of the requests of the client is that it has a system of notifications, that is to say, that when the user logs in, notifications appear in the sections in which content has been published while he was not there.
For now the only way I can think of is to create a table in the database that constantly stores the id's of everything it sees per section, that is, one row per user and one column per section, if the user visits the section 2 and article 25, id 25 would be saved for section 2. When the user logs in again, he will be notified in section 2 that there will be new articles.
Even though I could use this solution, I think there may be some more optimal, but I can not find it. If anyone knows of any framework, or any other way to implement this system, I would greatly appreciate it.
Greetings