ActivIdentity Software Engineer interview questions

I applied online and got a phone call and was interviewed by a Manager. He asked some questions on general Java. I was called in for an in-person interview in a week , which consisted of a written test, and 2 1:1 interviews, each with a group of 2 people. There were a lot of questions in the written test: immutable classes, linked list, some other PIE questions, etc. 1:1 interview tested knowledge of Collections API, EJB, Singleton, etc. One group which did the 1:1 was not prepared for the interview and did not know what questions to ask, another group was prepared and asked a lot of good questions. After I left I did not hear back from them at all, not even a phone call to say I was passed on.