Mike Sullivan's last 12 months: Development coach, AHL coach, NHL coach, Stanley Cup winner.
Mike Sullivan was hired in August 2015 to be the new head coach for the WBS Penguins. At that time his hire didn't get much attention. He had just won the 2015 Stanley Cup as a Player Development Coach for the Blackhawks. Before that, his time was spent mostly as a long-time assistant of John Tortorella after he coached the Bruins from 2003-2006.
While his hire as WBS coach didn't get much attention in August 2015, that quickly changed after the Penguins failed to meet expectations in the first few months of the season.