In late-August 2015, I was sent on behalf of the New York Post to visit Apple in Cupertino, CA, to get the low down on Apple News, in which the Post, and other News Corp publications like The Wall Street Journal, were participating.
Over four days, I designed and developed the templates for the Post, Page Six, and Decider in Apple's proprietary Apple News Format. At the end of each of the four days design reviews were held so the News team could check on our progress and make sure there weren't any hang-ups, and if there were, we had the oppurtunity to work them out with Apple's designers and engineers.
At the end of the four days, everyone left Cupertino more-or-less ready to go live when News launched a few weeks later.
Most of my time in Cupertino was spent "designing in code" but some design work up front was done in Sketch. For the curious, here's an overview of my Sketch document, which contains logo assets for Apple and some mockups for each property.