Enums in Rust are optimized for memory usage, resulting in smaller representations for certain types. The article explains how the Rust compiler employs techniques like niche optimization and memory representation to efficiently manage enum sizes, particularly in nested enums. It highlights surprising findings, such as the compiler's ability to use tags and niches effectively to minimize memory overhead.

Sourcing data from disk can outperform memory caching due to stagnant memory access latencies and rapidly improving disk bandwidth. Through benchmarking experiments, the author demonstrates how optimized coding techniques can enhance performance, revealing that traditional assumptions about memory speed need reevaluation in the context of modern hardware capabilities.