How to diagnose lag from mobs and farms in Minecraft

Heavy mobs, hopper chains and redstone machines can create tick load. First determine which world and region your burden is concentrated in.

Step by step

Get a spark profile at the problem hour. See which of the asset, block asset or scheduled jobs branches has the highest share.
Stop the suspicious farm safely by notifying the owner. Take the profile again with the same number of players and similar conditions.
If the farm is verified, make a small change that limits storage, transportation, or mob count. Check your world-wide Paper settings in your version's documentation.
Measure both MSPT and the output behavior of the farm. Evaluating the effect with just one short TPS screen.

Check the target and fallback backup before using a bulk asset cleanup command.