AddThis cofounder becomes Expa entrepreneur-in-residence

Hooman Radfar, cofounder of the Vienna, Va.-based social bookmarking website AddThis, announced he will become the first entrepreneur-in-residence (EIR) at startup studio Expa.
There, reports TechCrunch, he will work alongside two other social media trailblazers: Foursquare cofounder Naveen Selvadurai and StumbleUpon cofounder Garrett Camp. Expa has already raised $50 million.
To D.C.’s chagrin, Radfar had left the East Coast last October to resettle in the Bay Area. There, he created 10e9, a company that has advised and invested in startups like Speek and sweetgreen and where he’ll be staying on in a reduced capacity.
Here’s what Radfar had to say about the move on Expa’s website:

From pencil to bits, I’ve always enjoyed translating ideas to implementation in different mediums. As co-founder of AddThis, I was fortunate to collaborate with an amazing team to create and deliver publisher tools to over 14M websites reaching 1.75 billion people. The Expa team are true craftsmen – from Foursquare to Uber, they’ve created iconic products used by millions of people worldwide. I’m excited to embark on my next creative journey, building world-changing products with the Expa team.