A recruiter contacted me for a position. Then, I had two rounds of technical phone screens. The 1st phone screen was about 45 minutes, but the second one was two hours long. Then, I was invited for an onsite interview. Phone screen interviews were about algorithms and data structure questions. However, the second phone screen asked some questions in security because it was designed two-hour long. The on-site interview mixed the first and second phone screen topics. A few algorithm/data structure questions and one debugging question in C that was to find errors in a given code (on paper). Then, many questions on computer security topics were asked. Some questions were difficult, but many questions were average.