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% memory due to invisible padding bytes. Learn struct field alignment rules, fieldalignment tools, and field reordering techniques to reduce heap size and CPU cache misses.

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.