Pros
Riot is extremely competitive Work with some of the best in the industry, developing friendships that last for decades The work is fun, intellectually stimulating and challenging Coworkers and management often support and advise you Constantly pushes people who aren't adapting well to grow or move on Learned more here from people who challenged me to grow than anywhere else I've been We had several areas where I needed to improve significantly to fill the role the company needed and Riot did a lot to provide resources to grow.
Cons
Half the programmers are fantastic, most are very good, while a few specific unforgiving or under-informed programmers taint the perception of the entire discipline. When we finally reached a point where I started to turn around, my manager became impatient and expected results that weren't achievable given the gap between my in-development skillset and the unforgiving personalities in play. The large teams are great, the small teams are highly political and if you're not universally accepted on one, your smartest move is to get out quickly to find a different team, rather than repair the situation.