Is Facebook iOS app built in React Native?

Question

I came across an article that gave me the impression that Facebook's iOS app is built in React Native.

Does anyone know if this true?

Answer 1

One of my friend who was interviewed at FB 5 months ago was told that more than 80% of the application is still native.

I realized what is the point of moving over to React Native from Native for big companies? rather stay native and give the best user experience!