He was a Designer on Hearthstone Live Content development, featuring things like Fireside Gatherings, In-game Events and mainly Tavern Brawls
These are his own words about his departure:
Quote from Joe Magdalena
Hey everyone! I have some big news: I am leaving Blizzard. I’m still going to be making games, but it’s going to be very different from what I'm doing now. It's a huge opportunity to do something amazing. I’ll be talking more about that in the coming weeks. (thread)
I’m very proud of the work that I’ve done these past 14 years. I worked in WoW QA for the first 8 years, and got to spend these last 6 years on the Hearthstone team, as QA and then as a designer. I’ve grown a lot and it’s been a joy to put my own personal stamp on these games.
Blizzard has been such a huge part of my life – literally, my whole adult life. I started at Blizzard on the night shift the day before my 19th birthday. I’ve met and worked with so many great people. I’m proud to call some of the best game devs in the industry my friends.
To everyone at Blizzard: It’s been a privilege you’re who made working for this company great. I can’t wait to see what you all do next – and you can be darn sure I’ll be at the next BlizzCon!
I want to thank the whole Hearthstone community. I’ve loved talking with all of you and I’ve so appreciated the support you’ve given my ideas (even the wonky ones). I’ll miss giving you insights about brawls and my process, but I hope you’ll stick around for the next chapter.
Thanks for your time, thanks for the memories, thanks for everything. Well met, well played.
His first official video on Hearthstone channel were Developer Insights: The Season of Rastakhan
We wish you the best in your future adventures JOE! Thanks for your amazing work on this game!