It was really informal. I had to talk to other juniors first and I feel like I am being interviewed and I didn't want to show my portfolio to them but no choice. It was not a good experience.
The interview was done in 2 parts. First with junior staff then with the principal. It was relatively easy and straight forward- both parts required me to go through my portfolio.
I saw a job posting online and applied. I got an interview invitation almost right after that and went to do an interview. I think I met almost all staffs and they explained their ongoing projects.