I applied online. The process took 3 months. I interviewed at Riot Games in Mar 2014
Interview
Started with a Skype interview, followed by one phone interview. After that it was an onsite with 4 back to back interviews with 5 people. The people were all really nice, and the contact I had through HR was awesome at answering questions (I had tons).
Interview questions [1]
Question 1
If the world's oxygen delivery system was suddenly cut off and you had to come up with a replacement system, what would it be? Months later I still won't know how this should be answered :P