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.

"Why is our service slow?" "I don't know, the heap is only 200MB". "But we're allocating... wait, how much?" "12 terabytes". "...in how long?" "30 seconds profile". That's when we realized: we weren't running a service. We were running a garbage factory that occasionally served API requests. The Go garbage collector was heroically trying to clean up our mess, and we were blaming it for not cleaning fast enough. This deep dive into GC internals, profiling tools, and production war stories will teach you how to stop fighting the garbage collector and start working with it.