Applied through their site. Asked to take a video self-interview and a Codility test to test for "competency." They emailed questions for the self-interview ahead of time. The Codility test had two questions to complete in 90 minutes. The first was to find the area of two possibly intersecting rectangles while only counting intersecting areas once. Simple, but it may be hard if you haven’t taken geometry since grade school, like me. The second problem was easy, took 5 minutes; an O(n^2) time complexity solution. But there was a time complexity constraint, which made me redo the solution over another 20 minutes using a hash map to get log time. The two questions had nothing to do with data science or the position I applied for, but okay. Got a reply soon after for an interview through Skype. I live in the US, and the position is located in Tokyo. Supposed to be three back-to-back 30-minute interviews. One minute in, and I could tell that it was going to be bad. The interviewer did not give their name or introduce what they did at the company and interrupted me 10 seconds into my introduction. I was not asked any data science questions, just database design stuff not related to the position, but I answered correctly, I think. Asked to find IDs where the login date was consecutive for any three days using just SQL. I could not think of the answer, so I asked for the answer out of interest, and the interviewer laughed, okay. The interviewer, who was probably an engineer, obviously did not want to be there and showed no interest and even smirked at times, like it was a joke. After 15 minutes, the interviewer said she was done and told me to wait. I waited 30 minutes without a word, so I hung up. Got a rejection email the next day.

Tell me about yourself.

What are dimensional and snowflake models?

What are slowly changing dimensions?

How would you get all the records that are in table A but not in table B?

Given a login table consisting of IDs and dates. Find all IDs where they have 3 consecutive login dates.

Why do you want to work at Rakuten and in Japan?