The recruiters I worked with were very good, punctual and responded to emails in a timely manner. They were very accommodating to my schedule and did their best to prepare me for my interviews.
The coding challenge was reasonable although you had to manage your time very carefully and prepare your tools ahead of time as it was timed. The first phone screen was focused on practical problems that were of adequate difficulty and appropriate for the position in question.
The on-site interview is a TIRING experience, I was there for almost 5 hours and was exhausted by the end. I found the technical portion of the interviews quite easy and was really only challenged by one question in 3 hours. Questions were a mix of practical coding problems and CS fundamentals. The culture portion of the interviews was more difficult, there were a range of question from explaining technical topics to a non-technical interviewer, to more personal questions about why/whether you like to travel, how you started programming, how you look at design, etc.