Apple Senior Software Engineer interview questions

I was contacted by the recruiter.I had two telephonic interviews and then a day long onsite interview. All of it went very well. The HR provided positive feedback after the interview, but later changed to negative and there was no offer

A friend submitted my to Apple HR. The HR person email me to set up the first phone interview with a manager. The first one went well and the HR person then setup a second phone interview with another manager and said it will take 45 minutes for technical assessment. The second one also went well but haven't heard any thing from Apple yet (after one day).