Zenly ( http://zen.ly, millions of users, bought by snapchat ) has had an app coded in go and swift for ios ( and go and java for android) for a few years. Judging by the app, and the fact that it’s cross platform i’d say the go part does all the data processing part.

https://m.youtube.com/watch?v=R0oaOohl5jk ( in french but the slides are in english)