Inventing a language seems to be a rite of passage for every engineer at google.

Go, Dart, Carbon, Mangle, am I missing some?

I'm not criticizing, I would not dare as I'm creating my own language as well :P

Sawzall, a language focused around processing logs. Rob Pike led on this but use has pretty much all been replaced by Go. https://en.m.wikipedia.org/wiki/Sawzall_(programming_languag...

Dex, a language focused around array processing from the team behind the Jax machine learning library. Early stage research project. https://github.com/google-research/dex-lang

Rune, a language focused on security, early stage research project. https://github.com/google/rune

Wuffs, a language focused on writing safe file format handlers (parsing, encoding, decoding) https://github.com/google/wuffs