Not a bad process, but room for improvement.
After the initial application process it took a couple of months before I received an e-mail about the written portion of the interview process. Understanding that many of the positions posted on Riot's web page aren't necessarily open but filled when needed makes the amount of it took reasonable, but it also makes recalling the job a little more difficult. Fortunately, they don't remove these positions, so I was able to go back and review the specifics of the position.
The first part of the interview process were written exams. The first was an online timed test that felt like an IQ test. Which seemed a bit odd, but I can see where it may be applicable. The second portion of the process was a written "essay" style exam. I was given a specific scenario and was asked to solve it, within a week. A week was more than enough time, but the exam itself could have been a bit more clear. The written part was fine, but the attached example was confusing. After a bit, I was able to decipher it, it just took longer than I would have liked. After I understood what it represented, and what they were looking for, it was crystal clear, and I found myself wondering why it took so long to understand it in the first place. After submitting the exams, I received an e-mail requesting a phone interview within a few days. I was given the names of the Riot employees who would be interviewing me as well.
The phone interview took place between myself and two Riot employees, both were in various levels of "management", and as such, had a significant interest in who they were hiring. The phone interview itself was very general. The questions didn't seem to much to do directly with the job I had applied for. I assume that it was an oral exam type interview. Unfortunately, it did not go well. During the interview, I was consumed with answering the questions as best and as accurately I could. After, I realized what they were actually looking for with some of the questions.
One goal of the interview seemed to be to test my ability to think outside of the box. The problem was that the questions that were asked were very limiting. Given my actual knowledge on the subject matter, which they could not have expected, and the limiting factors given in the phrasing of the question itself, there was very little room to move when answering the question. It was a good and relevant question. There was a specific goal in asking the question and while they weren't looking for a specific answer, they were looking for something when asking it. I also felt very rushed when answering questions.
The second goal of the questions seemed to be them checking to see what kind of fit I would be within the Riot culture. No problems there, though.
I did receive a letter of rejection shortly after the phone interview. It was very timely, and I am grateful for actually getting a response. Many place I have interviewed at haven't even shown enough courtesy to let me know I didn't get a job after a face to face interview, let alone a phone interview.
Overall, the interview process is well done, quick and efficient, but I think they may pass over potential hires unwittingly because of that quickness and efficiency.