[fragmede]

Yeah, exactly. There is overhead simply because of the (necessary) cross-communication at that scale, and there's overhead from legacy support, but here's a thought experiment. Imagine that you've built the most perfect system from scratch that you can think of. Fast forward five years, and the business has pivoted so many times that system is doing all sorts of stuff it just wasn't designed for, and it's creaky and old. It just doesn't fit right anymore and even you want to throw it away and build a new one. So you form a tiger team full of the smartest people you know to greenfield build a new one, from scratch, but that's gonna take two years to write. (You think, hey, maybe we could just take this open source thing and adapt it to our purposes. To which I say, where do you think large open source projects come from‽)

How do you bridge the two systems? You build an interim system. But customers want new features, so those features need to be done twice (bridge+new) if you're lucky, three times (existing+interim+new) if not. Could a smaller team of 10x engineers come in and do better? First off, thanks for insulting all of us, as if none of us are 10x-ers. But no. There's simply not enough hours in the day.

We've all heard of large IT projects that failed to land and said "of course". But we don't hear about the huge ones that do. And plenty of them do land, quite succesfully, with these 200+ person teams where I, as an SRE, don't know the code for the system I'm supporting.

None of this is visible from the outside.