IBM Engineer interview questions

First there was phone interview with the hiring position manager. After it's passed, I got the invitation to go to the site for one day interview. I met with the manager and he/she arranged the whole day interview including presentation, 1-1 interviews with the group key members and the higher level manager. After 1-2 weeks, I got the notice of job offer.

Preliminary 1:1 interview to evaluate candidate's previous experience and potential ability. Followed by an hour long phone interview