JWP (JW Player) Software Engineer, API interview questions

there were 2 rounds of phone interviews. The first round was pretty basic with just talks about why I interviewed for the job. This was done by the HR. The second round was a code paired interview while on the phone with an engineer on the team. The third round was on site where I had to meet with 6 people for a total of 2 hours. Everything seemed fine and there were a few things about server architecture which I didn't know. I answered all the API stuff fairly extensively and spoke about my projects. It was very disappointing when I got a generic email saying that I had not been selected without giving a reason, especially after investing so much time to go and interview during work hours. Some personal touch would have been nice.