After posting my portfolio online I was contacted by a recruiter at Asana who said one of the designers referred me. They scheduled a brief intro phone call with the designer who referred me, which went well, then a few days later I spoke with the same designer over the phone, running through my portfolio for about 45 minutes.
On-site interviews were quickly scheduled, I was flown to San Francisco and put up in a beautiful inn a few blocks from the office. The next morning I arrived at the office, delivered a one hour presentation about me, my background, and 3 projects I had worked on. After that, there were 4-5 one-on-one 45-minute interviews with designers at Asana, with a break for lunch in the middle. The interviews were mostly informal and conversational, and there weren't any questions like "what's your biggest failure" or anything like that. The team seemed very friendly and I was excited with how well I thought the interview went. The recruiter explained that the team each rates my interview individually, then meets as a group to determine next steps. I was in their office for 5 hours.
I flew back home the next day, and the day after that I received a phone call from the recruiter stating that the group had a tough choice—although they loved my work, they thought I didn't have enough experience shipping products (fair enough—I had just graduated) and that I should contact them again in a year.