See poll. if other, state which company.
As a first heuristic, you should consider startups which are small and don't have well established and empowered HR departments. I hypothesize those will tend to be significantly less diverse than any of these companies.
Others
Intuit is looking like the most inclusive company of 2019
Baidu
My neighbor's corner-store is the least diverse business ever: such rampant nepotism.
Airbnb
How did you even come up with this list?
From chatting with friends.