I applied in October 2017, and there were a total of 3 rounds. First two rounds were online coding challenges. The first round I took in November -- consisted of simple debugging questions and logical reasoning multiple choice. I heard back in less than a week for the second round - which had 2 coding questions (similar to CTCI). In 2 weeks, they replied back to schedule a 45 minute phone technical interview. The engineer asked about projects then gave a tech question. I just made sure I talked through my solution and show how I'd improve. Understand the runtime and space complexity.