I agree about Facebook. They must have a great culture. Look what FB did for the JS ecosystem just recently—yarn, React, React Native, Immutable. Really excell

I agree about Facebook. They must have a great culture. Look what FB did for the JS ecosystem just recently—yarn, React, React Native, Immutable. Really excellent stuff which you not only need superb people but also a good culture. So, I'd say that excellent products, both the commercial ones but also open source, are a good indicator for 'culture'.