I'm not a game dev so please forgive me if this is the wrong place for this type of question but I'm looking for some resources to try and understand why games take so long to compile.

For context, I've worked with former game devs who've mentioned that builds can take anywhere from 4 to 6 hours to complete - even with a distributed architecture - depending on the hardware. That shit blew my mind. They said it has something to do with compiling shader permutations but didn't go into anyore detail. That said, I have a very primitive understanding of what shaders are but I mostly work with infrastructure and optimizing build systems.

Like I said, I'm not a game dev, im just curious. I appreciate any insight or resources you throw my way. Thanks!