The .gitignore Masterclass — Your First Line of Defense
Patterns, global gitignore, per-project patterns, common mistakes, and what AI agents forget to ignore
The .gitignore file is the bouncer at the door of your repository. It decides what gets in and what stays out. A good .gitignore prevents secrets, build artifacts, dependency folders, and system junk from ever entering your Git history.
A bad .gitignore — or a missing one — is how you end up with node_modules in your repo, .env files on GitHub, and a 500MB repository that should be 5MB.
AI agents are particularly prone to .gitignore problems. They'll create files, install dependencies, and generate build artifacts without checking whether those things should be tracked. Your .gitignore is the automated safety net that catches what neither you nor your agent remembered to exclude.
How .gitignore Works
A .gitignore file contains patterns that tell Git which files and
This lesson is part of the Guild Member curriculum. Plans start at $29/mo.