Milsoft Software Technologies UI/User Experience Designer interview questions

I was called on the phone first for appointment. Then, I was interviewed by one HR person and then entire team of ux people. I have filled a form full of questions which were completely about past ux experiences. All went very well. People were understanding and good listeners. After those interviews they had sent me a task which was relatively hard to understand and deliver. I had sent back the task in time. After that I was called again to let me know I was successful on the task. Then they invited me to another meeting with the director. The director was entirely negative from the beginning of the meeting. He seemed like he was trying hard to produce excuses not to hire me. After few minutes I realized I was trying for nothing. After a week they called me again to tell me they would not hire me without giving me a reason.