Good advancement opportunities for those willing to work hard
Pros
TripAdvisor is growing aggressively and this means there are plenty of promotion and advancement opportunities for people who have ability and are willing to work for it. I've worked at places where there are at least three qualified people jockeying for each opportunity to advance - TripAdvisor is NOT one of them. As of 2013 TripAdvisor is an excellent place for those who want to break through from senior to principal engineer or into management. Overall the level of bureaucracy in engineering is still low and it's possible to get things done without waiting a long time for management to make opaque decisions behind closed doors.
Cons
The location in Newton is not convenient unless you happen to already live in one of the western suburbs. TripAdvisor does not do a lot of fundamental R&D on new technologies. Look elsewhere if that is a priority for you.