The interview and hiring process was a great experience! First I had an intial screening over the phone with an HR person, followed by a very simple phone interview with a different HR person. A week later, I had a phone interview with the person who was going to be my supervisor. This phone interview took almost an hour but it went very well. It was of course a bit more complicated. I had a many questions where I had to put myself in the shoes of the competitors, and also do a little role play where I was supposed to convince a customer of the benefits of Trip Advisor´s services.
My final round was a set of 5 different interviews, which already took place in the office.
Some of them were a bit tougher than others, but overall the questions were easy and manageable. My advice, know the company and its numbers very well and of course, if you are applying for a sales position, know the product very well and imagine how would you sell it or how would you convince someone to continue using them. Also, the same as in any other place, ask as many questions as you can and the more complicated the question and more challenging for them, the higher chances you will have to succeed! ;)
Overall the interview process was a great experience! It took less than a month with 4 different rounds. People are extremely nice, polite and helpful (for instance, I had to take a cab and they paid it for me). I think one of the best things Trip Advisor has is the people working there! I had to chance to meet some of them, and everyone has an incredible energy, optimism and are extremly talented.
As long as you have the passion, the energy and the knowledge of the company and its products, you will be fine for an interview with them!