Yep, I also just left Meta/Facebook after 4 years working there. I did spend some of my time trying to see where Nim could fit (together with a few other folks

Yep, I also just left Meta/Facebook after 4 years working there. I did spend some of my time trying to see where Nim could fit (together with a few other folks that liked Nim at FB), the best area we could come up with was CLI tools that interfaced with many internal C++ libraries. Nim would be a great replacement for Python here (it's fast and typed) and its ability to compile to C++ makes interfacing with C++ super simple (at least in theory). It is true that Nim has the same problem as D to a certain extent: the ecosystem is limited and the benefit it brings over C++ just doesn't overcome that. A great example of this is why I said "in theory" above, in practice interfacing with C++ in Nim just hasn't been done enough to be mature. Multiple teams in a FAANG aren't going to take a risk adopting that.