JAI Software Developer interview questions

three rounds of interview were conducted during the process , first , round was aptitude round, second , round was technical round , and finally , we had hr round .

Even though the interview questions were straight forward, I heard back that one of the engineering managers didn't think they had a position open for my skills. Which is seriously dumbfounding: I submitted a resume with my experience, so why was it necessary to spend half a day there doing interview questions when it wasn't even necessary?