Salesforce Software Quality Engineering New College Grad interview questions

First recruiter called me and asked me if I was interested in the position. There was a phone interview with one of the manager. I did really well and they called me for onsite interview. Onsite interview started at 11 and ended at 5. Though the opening was for QA most of the questions were more like those asked to software developer. First interview was regarding data structures and object oriented concepts. They also asked a puzzle. The second interview was with 2 managers. It was an interview at lunch. It was one of the best. They also tried to sell the company by telling about community work that companies does. The third interview was about writing a java program. Also write JUnits for this program. The fourth interview was about the code I wrote. They asked some detailed questions regarding JUnits I wrote, asked me to pick top 3. They also asked me questions about database.The fifth interview was about test cases and a using s specific algo. The sixth interview was the most boring one. First they asked me what was written on my resume. So I thought this interview would go good but it turned out bad. They started asking about JUnits and asked to name the test which I defined. I asked them to make question more clear but could not figure out exactly. I lament the last interview. I was exhausted and my mind went into sleep mode. I did not hear from them for 20 days and had to send more than couple of follow ups to HR. I am surprised when they rejected me.