Amadeus interview questions

Pretty well structured interview procedure with a phone screening, a few online aptitude tests, two Skype interviews and a day long on site interview consisting of 4 rounds. The entire procedure took 6 weeks and was more or less on the easier side.

I was rejected in 3rd round technical. First round was of 1 hr. I was asked about my previous project, design pattern, some basic questions, and about the process. 2nd round was of 2 hrs ; I was asked about some design issues. 3rd was round again technical. I was asked about exception handling, basics, design patterns, and some advanced C++. Rejected in 3rd round. Dont know why. Questions were easy and answered all the questions except 2-3 in all the rounds