The process consists of a Codility online test and a pre-recorded video presentation.

There are normally interviews after this, but I did not pass the first step. It is not clear to me why I did not pass the first round, since I believe I perfectly solved the (easy) programming test on Codility. I think it is more the fact that I mentioned I changed my job several times in a few years, or anything on my resume that was not to their taste.

They did not explain why I was pushed aside, except mentioning that they were impressed by my credentials and experience, although they had a competitive pool of candidates (probably a standard formula to reject someone).

Codility: Find the sum of the area of two possible overlapping rectangles.

Pre-recorded video questions: They will be given to you in advance, so you will be able to prepare. But basically, why Rakuten, what can you bring to Rakuten, your work and skills, etc. – pretty standard stuff.