I got referred by the recruiter who told me TripAdvisor was interested in my mathematical background. We scheduled the Skype interview for a week from the date we heard from TripAdvisor. I read the reviews here on GlassDoor and figured that there will be a lot of Data Structures and Algorithmic questions. Unfortunately, it's been a while that I had a chance to work with them so I read the books/articles and watched videos to refresh my memory about those topics as well as complexity and programming knowledge. After the interview I did not have any news for a week or so. Then, they said they were not interested which is fine. The bad part was that I wasn't able to learn why.