PayPal Senior Software Engineer interview questions

Got the interview via consultancy and as part of the initial discussion they have more question on project and corresponding technologies like webservices, java etc. And first round telephonic is quite opposite and got questions on basic java, spring and maven. It's nice discussion but i've not prepared very well for it. As others mentioned prepare for core concepts will good enough for initial round.

First level was very basic in Java and algorithms. Most people would be able to clear it. Second level was little bit tough for me. Mostly they asked about Java garbage collection, how to write a good hashing algorithm. First they ask you to rate yourself in Java. Then they ask what all technologies/tools you have used. From there they start. They ask the next question based on your answer to the first question and go on...