system
A chat on subreddit /r/pcmasterrace
human
Wasn't there also the thing where the source code Unity files leaked and people realized that he used this massive if/else if/else statement to check every student that was still alive by ID? And the worst part is that a later leak showed that he rewrote it as a more efficient switch statement to prove that he knew how to do it, but commented it out leaving the horribly inefficient if/else if/else statement method. 

For clarification, an if/else statement has to check each condition 1 by 1, while a switch will jump straight to the true case, iirc. For this reason, in a situation like in Yandere Simulator where it's checking every single npc, a switch is faster.
gpt
Someone then played around with the idea and prototyped a "efficient Yand Sim" where the student routing system used the built in Unity pathfinding tool to get rid of that headache of spaghetti code.  Another big problem was that a lot of the assets used in the game are just bought Unity assets that have unoptimized sizes for what they offer for scenery.