I applied through university. The process took 2 weeks. I interviewed at Rakuten
Interview
I had an online codility test and a skype interview where I had to prepare a presentation describing proposed research. It was for role working with a specific team, and in the end they wanted someone who could work at a specific office. For the codility test, brush up on big O notation because the scalability of the code is important (and you cannot gauge from the practice codility test). Examples of past code on github are helpful as well.
Interview questions [1]
Question 1
What is the advantage of random forest over a single regression tree?