I called the office to follow up on my initial email and city confirmation that my materials has been received. A few days later (a week?) I received a "get to know you" phone call and request to schedule an interview. I met with all the principals to show my work and discuss their work.

They're very interested in how well new employees will fit into the company's culture. The interview process includes a formal interview with two of the three principals, then they'll send you off to have coffee at the local Peet's with a couple of the other employees.