I'm sort of interested in what their migration process was like. Particularly because I have seen so many HN posts "written in X converted to Y success stories

I'm sort of interested in what their migration process was like. Particularly because I have seen so many HN posts "written in X converted to Y success stories". Most companies just can't drop everything and do a code conversion. They need to do it incremental. It seems with Swift this should be straightforward but maybe its not (I have to imagine its easier than going X to Golang which seems to be in vogue)? IMO would have found it far more interesting to hear about the migration than why Swift is superior.