Choosing Between Push and Pull Fan-out

For each scenario, state whether fan-out-on-write (push), fan-out-on-read (pull), or a hybrid is the better fit, and justify in 2-3 sentences using the trade-offs (read cost, write cost, staleness, wasted work):

1. A private messaging-style "close friends" feed where each user has at most 50 followers, all mutual and highly active.
2. A public figure with 30 million followers who posts twice a day.
3. A feature showing "recent activity from teams you're in," where each team has 5-8 members and everyone reads the feed constantly through the workday.