I applied through an employee referral. I interviewed at Viridien in Sep 2015
Interview
Phone interview, they will ask when you can work, and ask mathematical question. They are all simple questions. More like high school problems. If you forget the concept, and the way to solve the problem, you can review it and pick it up very quickly.
first round. in the format of phone or zoom. I was asked some math questions/basic physics questions. Some of them are like middle school math contest questions. Some of the focus on signal processing. I don't remember all of them. But if you are good in high school. you will be fine.
I was interviewed by only one person. They asked me why I wanted to work for them and my skills. They asked me about my thesis and if I was avaiable to move out of my country.
Two rounds of phone interviews. First round to describe yourself about your research and so on and asked some simple math question. Second round asked some brain teaser and more math questions
Interview questions [1]
Question 1
some brain teasers related to geometry algebra questions as well as classical probability