The primary automated test suite at 500px contains over 11000 automated examples written in Rspec with Capybara. These tests run on development branches, as well as each time a commit is merged into master. They take an average of 20 minutes to run across six threads on Semaphore. We have dedicated test engineers (and co-ops!) responsible for helping maintain this test infrastructure as part of the 500px quality process. Reducing the run time of the test suite can have a significant impact on de...