After three months working inside Claude Code daily, I learned something: the difference between “cool demo” and “replaces half my SaaS stack” is a file that doesn’t even get created half the time.
CLAUDE.md.
People skip it. I skipped it for weeks. It feels like documentation homework. That’s the wrong way to think about it.
CLAUDE.md isn’t documentation. It’s navigation infrastructure.
Without one, Claude starts every session blind. Where are the tests? What’s my file structure? Where do configs live? What are my conventions? Every session, you’re re-explaining your project or watching it grep around hoping to stumble onto the right file.
A good CLAUDE.md is a router. It points to subdirectories. It documents local conventions where they matter. It gives structure Claude can follow without me typing the same explanations every time I open Terminal.
The shift happened when I stopped treating it like a README I wrote once and started treating it like infrastructure to maintain.
Since then, I restructured my entire workspace around this one file. Individual project directories, each with its own CLAUDE.md explaining tech stack, directory structure, and conventions. Now when I switch from agency work to my research platform to personal projects, Claude already knows where everything is and how it works.
My project became navigable. My context stayed clean. Work that felt like constant re-explanation became fluid.
Context quality is the difference between “this could be useful someday” and “I use this 40 hours a week.”
Most people are building on sand because they skipped the foundation.
Don’t skip the foundation.