Getting a shot at working on Hearthstone isn't easy. To work on Hearthstone, you have to be pretty freakin' good at Hearthstone.
You also have to have other qualifications to apply for a job at Blizzard, sure:
But for Schaard, the requirement that would go on to take the most work was attaining a "legendary" rank in Hearthstone. In this video, Schaard takes you through his journey to become a great Hearthstone player -- all so he could eventually apply to work at Blizzard.
It's super-gratifying to see Schaard attain the rank, especially considering that he started out as a player who wasn't particularly great at the game. Unfortunately, by the time Schaard became a legendary player, the position at Blizzard was filled. Boo! Still, it's an amazing story -- and who knows, maybe the next time there's an opening, they will keep him in mind.