This is part of a series where I’ll walk you through the entire Go compiler, covering each phase from source code to executable. If you’ve ever wondered what happens when you run go build, you’re in the right place. Note: This article is based on Go 1.25.3. The compiler internals may change in future versions, but the core concepts will likely remain the same. I’m going to use the simplest example possible to guide us through the process—a classic “hello world” program: