A practical guide to understanding how CPU caches (L1/L2/L3) impact Go service performance, with benchmarks on modern hardware.

Your Go structs might be wasting up to 32% of their memory due to invisible padding bytes. This deep dive into struct field alignment reveals how the compiler arranges memory, why field order matters, and provides benchmarks showing real memory savings. Learn the simple reordering rules that can shrink your heap, reduce GC pressure, and improve CPU cache efficiency.

When thinking about performance, it's easy to focus on Big O notation. But in Go, the difference between the Stack and the Heap is often the difference between a service that scales and one that chokes on GC pauses. This post explores escape analysis, the "Pointer Myth", and why passing by value is often 40x faster than passing by pointer.