Meta Software Engineer interview questions

I had a colleague from my recent summer internship talk to his friend who worked at Facebook refer me. About a week later a recruiter reached out to me to schedule a phone interview. I had 3 interviews in total. The first one was an initial screening interview over the phone with the recruiter where we simply went over my CV for 30 minutes. A few days later she scheduled a Skype interview with an engineer from Menlo Park. The interview was technical and I managed to solve 1 question just about on time, with a few minutes left for questions for the engineer before he had to run off. I was surprised to see the next morning that they wanted to move forward and schedule a 2nd interview with me. This time it would be with another engineer but over video conference. The interviewer was very kind and gave me a hint when I was moving in the wrong direction with my solution. Again, I managed to solve the solution just about on time with a few minutes left for questions.

Was called onsite directly as I was local to Cambridge, MA. A Sr. Engineer interviewed. He was welcoming and willing to help. It was a typical white board coding interview. Very professional and very helpful. Recruiter called and asked me to come onsite as the position was local. They gave responses very quick. I said to my interviewer that I am not interested in web development but interested in back end (may be its a mistake, as its facebook).