One year ago, I realized I was spending way too much time fixing libc++ issues that could have been prevented by simple pre-commit checks, and I implemented pre-commit CI for libc++ using pre-existing Phabricator integration. One year later, I can see how instrumental this has been in making libc++ better on several fronts - increased contributions, higher code quality, increased contributor diversity, etc. This talk will go over how the CI for libc++ is set up and how other LLVM projects can follow that lead. It will also explain what the main difficulties were and how this seemingly simple piece of infrastructure completely changed the dynamics of the project for the better. My goal is that after this talk, folks realize the immense value that pre-commit CI can bring to their project and understand how they can make it happen with the current LLVM infrastructure in a reasonable time frame.