A good friend -- advertising-focused designer with lots of Photoshop and Flash experience -- has been exploring this transition. I also have a "unicorn" title m

A good friend -- advertising-focused designer with lots of Photoshop and Flash experience -- has been exploring this transition. I also have a "unicorn" title myself (data scientist, lol), and think this would be an interesting transition for him. He doesn't know where to begin though. If he wanted to move to "tech-friendly designer," what should he pick up? Sketch? React?