https://techcrunch.com/2019/03/14/chris-cox-leaves-facebook/

13-year Facebook veteran, Chief Product Officer, and the spirit animal of the social network Chris Cox is departing the company after two years of seeking to do something new. Cox’s exit is part of a big executive reshuffle as Facebook embarks on prioritizing privacy through messaging, groups, Stories, and integration of its chat features.

CEO Mark Zuckerberg explained the departure of his long-time friend, saying “For a few years, Chris has been discussing with me his desire to do something else . . . But after 2016, we both realized we had too much important work to do to improve our products for society, and he stayed to help us work through these issues and help us chart a course for our family of apps going forward. At this point, we have made real progress . . .  As we embark on this next major chapter, Chris has decided now is the time to step back from leading these teams.”