I wanted to share an interesting discovery. If you’re using Capybara then you might be able to speed up your tests considerably (5 times in my case) by moving the database to tmpfs. I wrote an article showing how: https://www.gregnavis.com/articles/how-to-tune-your-database-to-make-tests-faster.html . The same technique should work in other frameworks (and languages) as long as you don’t wrap test cases in transactions to clean up after them.