What should be the architecture for the following type of news feed?

I am in the process of building a news feed system. This is not the usual feed where 2 people are connected to each other. This feed is a 1:1 connection between the user and my system.

My system publishes a list of information to be displayed in the user's feed. This information's data structure can vary depending on the type of info published. I have read a few articles on news feed but all of them take Facebook as example where the users are already subscribed to each other and the push model works perfectly.

In my case each user is subscribed to only my system which sends out these feeds.

How do you go about designing such a system?