~/.gitignore

Set a .gitignore file to apply across all projects on a local machine with:

git config --global core.excludesfile ~/.gitignore

The contents of the Status OK monorepo's gitignore are:

!tags/
!tmp/cache/.keep
*.pyc
*.sw[nop]
.DS_Store
.bundle
.byebug_history
db/*.sqlite3
log/*.log
rerun.txt
tags
tmp/**/*

One example pattern is the line matching files with .swp extensions: It ignores temporary files created by Vim.

Those files could be ignored in each project but not every teammate on every project is also using Vim. For them, that line is unnecessary.