[Kihashi]

You should look at some of their dev blogs. Their engineering team has done some pretty remarkable things, like re-writing the game server to be deterministic so they could better deal with problems that occur in pro play[1]. They've also talked a bit about the past and future of the game engine specifically [2]. They also have blogs talking about operations- taking the game from something written by 2 dudes in a dorm room to being one of the most played games in the world- how their stack has changed, how they're set up to do patches and rollbacks, how they do their internal testing and playtesting, etc.

[1]: https://technology.riotgames.com/news/determinism-league-leg... [2]: https://technology.riotgames.com/news/future-leagues-engine