I get asked why to even try Ruby dynamic test suite split over deterministic split across parallel CI nodes.
I show you a case study of 7 minutes shorter CI build timing I got from one of the CircleCI users running tests with knapsack_pro ruby gem that I built.
Here is the article that describes how to configure CircelCI 2.0 parallelization and how to run your Capybara feature specs with Selenium webdriver and Chrome headless. You may find this useful.
Would you like to see more tips? Please let me know.