Interesting. Obviously they view it as a core competency. This would seem like a non-obvious and unnecessary expense to many, but (on the Tesla side) differentiates them from other automakers. Whether that results in a barrier to competition... we'll see.
I only know of low-level tools being open sourced like service meshes, RPC clients, event busses, and metric servers. I’ve never seen internal applications open sourced. Do you have an example?