Anyways, I don't think I did put the chicken and the egg idea here, so!!
The chicken and the egg is my idea for a "test" for admins when they first create a server. It's hardcored in to ensure the person starting the server knows what they're doing, at least a little bit. Like a puzzle that needs to be solved.
The rules of this problem are simple; in order for mobs to start spawning there must be both a chicken and an egg present on the server. A chicken despawns instantly without an egg, an egg despawns instantly without a chicken.
The solution to this is for an admin to run the tasks in parallel, they happen at the same time, and because the tasks are processed at the same time, both come into existence together. No despawning, and you're all good to go.
c!Dream when starting his own server encountered this problem with no formal training. He got stumped by this for awhile, before finding a solution he was very proud of!!
One day, someone, probably c!Phil is looking through the server code and realizes that the server. straight up. Isn't using any parallel processes. He's not even sure how that's possible. It shouldn't be possible, because you need at least one parallel process to start your server and spawn mobs.
Since he can't figure it out Phil asks Dream how he solved that initial puzzle, trying to figure out what's going on. Dream is very happy to explain his solution!!
Start trying to spawn a chicken in a loop, basically spamming the command.
Paint a painting of an egg in an item frame.
Take an actual item frame and place it in front of an observer
Pause ticking so the observer can't update
Replace the item frame with the picture of the egg in an item frame.
Resume ticking.
The Observer now believes there is an egg that has been placed in the item frame, because the observer believes there is an egg, the server now believes there is an egg.
Because the server now believes there is an egg, it allows the chicken to spawn. Once he has the chicken, c!Dream spawns in a real egg.
Profit
Dream even kept this setup in a tiny little bedrock enclosure so nobody could mess with it. He shows it off to Phil whose just stuck between awe and horror that this worked and the broader implications for what kind of weird rube-goldberg ass server they're on right now.







