4 rounds, one 30min phone call, one technical itw where you talk about your projects and the difficulties related to it, two itws to talk about your values and how it aligns with Riot's culture.
Overall super great experience, friendly vibes and very conversational. The interviewers tell you at the beginning of each interview what they expect from you so there are no traps and you are encouraged to ask for clarification at any moment - they put us into the best position possible to reply as best as we can. The interviewers were passionate about their job and it really showed that they liked what they were doing, describing their experience at Riot in a very positive yet realistic way.