Some phone screens followed by on-site interviews. Phone screens were more focused on probability-type brain teasers, while on-site interviews were more focused on cases and typical behavioral type questions. People were generally quite nice, but frequently late / absent to an unprofessional degree. At one point, I was sitting in my interview room alone for an hour due to last-minute rescheduling. Not to mention a pretty tremendous oversight by my recruiter in helping me to prepare.
I suggest that you practice a lot of cases before going out. All sorts of cases. Prep as if you are interviewing for consulting. Structure is valued more than creativity. To Riot's credit, they are very upfront about what they are looking for and aren't going for a bait and switch. They are genuinely striving to hire good fits.
My other advice for potential interviewees is to consider this as a business-oriented role first and foremost. Be realistic about how the role could fit into your professional development, and avoid overweighting your decision to expected personal fulfillment. As a player, I was under the illusion that the position related more to game development (such as balancing) but it was made clear to me on-site that everything comes down to the bottom-line. Not that anyone misled me; this was made clear through the cases, but really driven home by a somewhat aggressive interview where, in retrospect, I feel that I was fished for new revenue ideas. I've noticed this trend at other companies - and have friends who have corroborated this sentiment - and it isn't a good feeling.
I didn't get an offer, but if you do you should definitely consider - even as a huge fan/player of the game, what if you were to grow out of it or move on to another game? Well, there'd you'd be, working day after day in the absence of what was probably your largest motivation to join in the first place- your genuine passion for the game/community. At the same time, leaving Riot is an uphill battle due to both the general sense of complacency/comfort there, and negative associations from potential employers of working at a video game company. Several of my interviewers - whether explicitly or through their actions/demeanor - made it clear that this was the sort of position they were now in. Several of them talked openly about how they no longer play and moved on to other games - probably because it's so normal to have such conversations at Riot, that they had no sense of applying a filter around interviewees who might be shocked by this sort of talk. This creates a dilemma for Riot - either hire businessy-people with little attachment to the actual gameplay/community, or hire actual players who may actually be overly committed to the player experience to the extent that it may disrupt the natural order of business. Really consider your motivations for accepting a potential offer: Riot has all the pressures and prioritization concerns of any business.
Hiring manager had very nice things to say and some constructive feedback about how I can approach the interview process better in the future, but after thinking it over, I have decided against reapplying. I was hoping to join Riot to apply analytical skills outside of a typical business mentality, but the interview process made it clear that this expectation was unrealistic. I am certain that many people thrive, both personally and professionally, at Riot - but there are also others who have clearly lost their spark along the way.