Arup International Development interview questions

The interview process seemed very informal. I was invited to come to the London office to attend the interview which was conducted by two Arup employees. The whole interview lasted approximately an hour but it didn't feel like I had been in there for that long. The interview was competency based questions ie Describe a time you felt under pressure and how you dealt with it? Describe a time you had a large work load and had limited work load? Describe a weakness and how you deal with it etc