There are close Google <=> SpaceX links too... The Starlink backbone network uses Google Cloud features that appear custom built/aren't available even to big customers. Nearly all Tesla tech seems built on top of Google tech - for example they use various private maps API's for the in-car map display. And everything is built on top of protocol buffers, google's in-house RPC/serialization format.
Protocol buffers have been public for 10+ years (since 2008 according to Wikipedia). Given the mobility between tech companies, it's hardly surprising that the same ideas / solutions are reused across companies.
For instance, Elon Musk has mentioned the Materials Science team he has works for all 3 companies Tesla,SpaceX,BoringCompany etc...