Morgan Stanley Summer Analyst - Technology interview questions

I've received an invitation to a telephone interview after about 2-3 weeks. The telephone interview was delayed for about two weeks because of unknown reasons. I had to contact HR multiple times to finally get it done. The interviewer was kind, calm and inspiring. He asked me about my motivation and technical skills. The interview went very well. The response to the telephone interview was again significantly delayed. It took about one week to respond because the interviewer went on holiday before giving the outcome. I was rejected and requested feedback but they said that they could not provide me with it. It's very unprofessional of them not to, as I was really expecting a good outcome.