I made the connection with LB through multiple grad school friends who work there. The pre-interview process involved several preliminary conversations at a conference and by phone.
The interview itself was a full day in Atlanta, with a series of technical interviews lasting either 30 minutes or an hour. I gave a talk on my recent research and got intelligent questions from the audience. The CTO clearly knew a lot about pointer analyses (which I used a black box in the work described in the talk) and asked probing, but fair questions.