They're a company, and just like any other company you'd apply to work at, you give them your resume and apply for your desired position. They look for the best and the brightest though, and they're pretty strict when it comes to the people they hire, so make sure your resume is stunning. You can read more about what Riot is looking for, as well as apply for open positions here.
That being said; You've posted this in the wrong sub-board, so I'll be locking this discussion. The best place to have this kind of discussion would be in the General Discussion sub-board. If you have any further questions, I encourage you to ask them there.
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