Member-only story
Fatty Structs: Casey Muratori’s Approach to Data Structure Design
Understanding the philosophy behind dense, practical data structures in performance-critical programming
If you’ve spent any time in the game development community or followed discussions about performance programming, you’ve likely encountered the name Casey Muratori. Known for his work on game engines, his “Handmade Hero” project, and his outspoken criticism of modern programming practices, especially OOP, Muratori has consistently advocated for a more direct, performance-oriented approach to software development.
Now, here’s something interesting I discovered while researching this article: the term “fat struct” appears to have been coined by Muratori himself. In discussions on the Handmade Network forums about entity systems, Casey directly uses this terminology when explaining his approach to data structure design, describing how a “fat struct” approach can be more effective than discriminated unions for game entity systems. This perfectly encapsulates one of the core principles underlying his programming philosophy: the idea that data structures should be dense, practical, and designed around actual usage patterns rather than abstract theoretical principles.
