The process is not that long compared to other big companies. It includes 7 steps:
1) video self-interview: they will send you a link to a platform where you will have to record a video of yourself answering few questions.
TIP: the HR will tell you these questions before this video, so prepare your answers in advance. Never forget that Rakuten is a Japanese company and, as such, people there really care about the passion you have, how polite and kind you look, and how convincing you will be in the video.
2) Coding test: an exercise to do on Codility platform. It's normally very easy and you will have 1 hour to do it, when you want (deadline is in a few days). TIP: get to know Codility in advance to get acquainted with the platform. Also, prepare a bit on books like "Cracking the Coding Interview", you will see that the exercise is one of those classical exercises with, maybe, a small trick to take care of. In one entire hour available you can even look for some help on Internet. You can't see the result of the tests, so you will have to fry until you receive the follow-up email from the HR.
3) First interview: it will be with the team leader of the team you have applied for. Very easy interview to get you know you and your motivation, and one or two questions like "what would you do if ...". very high level questions regarding technical stuff, so be prepared a bit about the general topics of the field you have applied to work for (e.g.: for Web development, refresh your memory about HTTP, caching, CDN, scaling, etc...).
4) Second interview: it's with the senior manager of the department. It can be more technical than the previous one. Less about motivations and such.
5) Books to read: between the 2nd and the 3rd interview, they will send you two essays written by the CEO of Rakuten, Mikitani-san, that you have to read and send your review. I found them very interesting and they can really be helpful to get insights about the culture of the company.
6) Third and final interview: it's with the director of the division. Do not think it'll be the easiest one because in Rakuten this position is also taken by CTOs (Rakuten acquired many smaller company and their CEO become CTO), who are extremely technical people. In my case it was not technical at all and the interviewer was very nice and gave a lot of useful information about the company. No questions about the two books read before the interview.
7) Meeting at Rakuten HQ in Tokyo to discuss about the contract.
The process took around 2 months, but it went smoothly and all the people were very nice and kind with me. HR did a very good job with communication via email and skype.
