On-site interview with LinkedIn: 4 interviews + lunch. The interviews were not too hard except for one (listed below). The interviewer was difficult to communicate with; even though I talked out loud and explained my implementation, he had trouble understanding it, which caused him to change the question partially midway through when he realized it was not what he had intended, which added to the confusion. Sometimes you just know when an interviewer is not getting you, and it was one of those. All other interviewers were easy to communicate with; it was great chatting about their work at LinkedIn.

Word ladder problem.