I heard that Meta also has a monorepo but most of their open source projects are very community driven. I think it is corporate mandate thing, no resources to be spent on open source and not tracking open source contributions as part of career development.

Meta does have a monorepo but their open source stuff lives outside it. Or at least it did when I worked on PyTorch (2019). I did all my work in the separate open-source PyTorch repo and then commits got mirrored back to the monorepo by some automated process.

You could also build and run it using completely standard tools; you didn’t need to download random internal source control software etc. like you do for e.g. Chromium.

Curious about the organizational dynamics around this kind of decisions. There is no reason why google couldn't do the same.

I assume there is little will internally because everyone there is so focused on their performance reviews and helping external people using google open source projects is not tracked by that.

I think it's more of a strategic difference. Google seems like their long term planning involves thinking about open source less than Meta's. They're more wait-and-see about it.

React must've been destined to be open source from the get go: gotta create a mountain of js to hide in so the users can't strip out the malicious parts. Kubernetes on the other hand could've been internal forever and still would've made sense. It just happened to later make sense to open source it (it feels lopsided to me, like they kept certain parts secret. It wouldn't feel that way if they had planned it as OSS from the get go).