They contacted me and set up an interview. The first interview was with an engineer lead and he talked more than I did. A little weird but it's fine. In the second interview, an engineer asked me to implement reduce() in Ruby. I was not very familiar with script language and he is not good at explaining the concept and very impatient. In my opinion, if I understand the way script language works, the interview would be pretty easy. But there is a learning curve and with all those new terms, I didn't get the concept very quickly. There are a couple of questions, and he expected me to provide the correct answer in seconds, otherwise, he told me the answer without letting me try to figure it out. The interview was supposed to be one hour, but he told me all answers and finished it in 30 minutes. I wouldn't want to work with someone impatient. Everyone needs some time to learn. If it is for an engineer position, the interview is Ruby and you have no choice! I did brush a little bit ruby before-hand, however, I found that it was very distracted to use some new language. I paid a lot attention to the syntax, but forgot about the logical edge cases. In sum, the interview is very informal.