Hearthstone executive producer and longtime Blizzard dev Hamilton Chu has left the company, marking the second high-profile departure the Hearthstone team has seen in the past week.

Chu revealed his departure over the weekend in a Twitter reply to Ben Brode’s own announcement that he was leaving Blizzard. While Brode’s announcement came with a forum post detailing his decision to leave and “embark on a new journey,” Chu has only mentioned his own career shift on Twitter thus far.

His bio on the website now notes that he is “starting up something new,” potentially involved with the unannounced new endeavor mentioned by Brode last week.

Chu himself has been with Blizzard in a variety of roles since 2008, and has worked at both Electronic Arts and Bungie, among other studios, in the years before joining up with the Hearthstone dev. He notably spent six years in production roles at Bungie in the late ‘90s and early ‘00s, working on games like Oni, Halo, and Halo 2.