I've worked on build systems quite a bit across a disparity of languages, frameworks, operating systems and engines. I've constructed some really big build systems spitting out 100's of SKUs across a dozen target platform, and I've built studio-wide build systems that again, spit out hundreds of SKU's across dozens of projects, with hundreds to thousands of programmer and artist hours per day of code and art and other binary assets pouring into the version control every hour of every day.

And the universal constant in all build systems is always a problem of management. I've turned 7 hour builds into 7 minute builds, and management doesn't care. I've saved literally thousands of hours of programmer time per year on projects, and management doesn't care. Build systems are a cost center. Always neglected, never funded, and not seen as critical infrastructure.

Build systems, at the end of the day, no matter the language or target platform, are never really that complicated, we just tend to over-complicate them. What I really want, if I had the time to implement, is a build file system.

All that said, I'll never go back to working on a big build system without having a PM that insulates me from the unreasonable demands of being woken up at 4AM by a Producer absolutely frantic because "the build system isn't working at all!" but when checking on the problem, it's because a developer checked in some code late and night and then went home. I have some serious trauma from those years of my life.