The hard part of the interview process is that it is quite long; each of the individual interviews felt fair.
Prior to the final round of interviews there are: A values interview, a quick take home, a tech interview that goes over the take home, a communications interview.
And then a final round that is two technical interviews and another values interview.
The recruiter was very helpful in telling me what general areas to prepare for for each interview stage. Riot puts more weight on values and soft skills than other companies I have interviewed at (which is nice), but definitely make sure you come up with examples from your work for the soft skills interviews.