I am developing an activity feed for a basic social app: you can follow people and people can follow you back. When you follow someone, content from that person will appear on the activity feed. I am debating wether the feed should show content posted by that person before I followed her, or if it should show content made only after I started following her.
I see that Twitter implements the first option, and Instagram the latter.
I can’t really understand the pros and cons of each. What are some good practices about this?