Not a super hard interview, but definitely not easy. I had 3 phone screens followed by 6 1-on-1 interviews onsite. Luckily, the recruiter I worked with was very helpful. Had a difficult time communicating with one interviewer(both on the phone and onsite), but in general everybody was extremely professional. As for the answers to the questions, they aren't as important as your approach to the problem. The interviewers generally tend to push you in the right direction if they think you are off track .
Questions mostly focussed on string manipulations, scalability, multithreading, design patterns, and data structures. Definitely brush up on the basic data structures.