A Taxonomy of Tech Debt

Hi there. I’m Bill “LtRandolph” Clark, and I’m the engineering manager for the Champions team on LoL. I’ve worked on several different teams on League over the past years, but one focus has been consistent: I’m obsessed with tech debt. I want to find it, I want to understand it, and where possible, I want to fix it.

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Posted by Bill Clark

Profiling: Optimisation

Hi, I’m Tony Albrecht, an engineer at Riot, and I’m a performance junkie. This is the second part in a series on how to optimise your code. In Part 1, Measurement and Analysis, we learned how to find and analyse performance bottlenecks in our sample code. We surmised that the issue was due to slow memory access. In this article we’ll look at how we can reduce the cost of memory accesses and thereby speed up our program.

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Posted by Tony Albrecht

Animation in the League of Legends Client

The League of Legends client UI resembles many traditional web applications, both in its choice of technology (JavaScript/HTML) and its range of functionality. However, the League client (the pre-game experience) is not a traditional web app - at its core it’s a game UI with high-quality visuals, which led to several interesting challenges along the way. I’m Richard Ye, a software engineer on the League of Legends client, and I’m going to talk about one of the major development challenges we encountered in the client UI: animation.

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Posted by Richard Ye

Profiling: Measurement and Analysis

Hi, I’m Tony Albrecht, an engineer at Riot, and I like profiling and optimising things. In this article, I’m going to walk you through profiler basics and analyse some example C++ code as we profile it on a Windows machine. We’ll start at a very high level and delve deeper and deeper into the bowels of the CPU step by step. Once we identify opportunities for optimisation in this article, we’ll implement changes and explore some real-world examples from the League of Legends codebase in a future article. Let’s begin!

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Posted by Tony Albrecht


The Evolution of Security at Riot

Hey folks! We’re Mark Hillick, Jason Clark, and David Rook from the Riot Security team and we’re here to discuss how the security program at Riot has evolved over the last 4 years. This is our first article in a series of security articles so it’ll be more high-level, but keep an eye on the tech blog in the future for all the juicy techy bits.

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Posted by Mark Hillick, Jason Clark, and David Rook



Determinism in League of Legends: Implementation

Taking the League of Legends game server from a nondeterministic process to its current state required almost a full year of effort from multiple engineers. As a side benefit of this effort, we holistically improved the codebase’s robustness, discoverability, and maintainability. We removed swaths of dead or redundant code and created new opportunity spaces for gameplay exploration.

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Posted by Rick Hoskinson

Determinism in League of Legends: Introduction

Hi, I’m Rick Hoskinson, an engineer on the Deterministic Disaster Recovery team, and I’m here to talk about how we gave ourselves the power to turn back the hands of time in League of Legends. In this series of blog posts, I hope to give you a glimpse of what that work looked like, juicy technical challenges and all. In this first post, I’ll introduce the problem and how we chose to solve it. 

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Posted by Rick Hoskinson