A single Like is measuring as taking significant time on the PostgreSQL database as a INSERT, and comments and postings are even higher. As in 1/2 second of real-time for each and every one.

The lemmy_server code that does https outbound pushes is also not thoughtful about how 20 likes against the same server hosting the community is triggering 20 simultaneous network and database connections… concurrent activity isn’t considered in the queuing from how I read the current 0.17.4 code, and it blindly starts going into timing loops without considering that the same target server has too much activity.