Talk through the portfolio and explain the design process. Explain your skill sets and what you know about the firm. Can you make physical models? How long will you work here, etc.

Very formal interview and application process. You first have to apply online and then the first step after submitting online application is a recruiter contacts you, you speak with them on the phone for screening I suppose. Then the HR person contacts you after and sets up an appointment to come in to the office. After that the interview is in person with the architectural staff. I received an office a few days later. The process is a bit long but for such a big corporate company is normal.