John Ternus takes over from Tim Cook as chief executive of Apple in September. A company insider, Ternus is moving up from his role as head of engineering to take control of the entire $4tn £3tn business. Apple is a vast, successful tech company and one of the most recognised brands in the world. But it faces challenges nonetheless. Here is a look at Ternuss in tray . Artificial intelligence has been a surprising weakness for Apple, at least in the eyes of some investors. It has stood on the...