How did Knapsack Pro start? In mid-2014, I worked on a client project where we had slow RSpec tests taking ~15 minutes, and I was looking for a way to save time and run faster CI builds. So I came up with the idea for an open-source Ruby gem called knapsack (the idea for the name came from the knapsack problem). The knapsack gem was helping split tests evenly across parallel CI nodes so you could leverage parallelism on the CI server.
I added a link to the Knapsack Pro beta landing page in the readme. Once ~80 people signed up for the Knapsack Pro beta, I started building it in March 2015. At the end of 2015, I had a working version and started promoting it. In mid-2016, first paying customers validated that improving the product further makes sense. Feedback from users helped me add more features and improvements like Knapsack Pro Queue Mode, which splits tests in a dynamic way across parallel CI nodes to ensure each CI node finishes work at a similar time. Thanks to that, CI build is as fast as possible, and there is no bottleneck in your parallel jobs.
Nowadays, hundreds of developers use Knapsack Pro every day to run their CI builds faster. The free knapsack gem was downloaded over 100 million times. In addition, Knapsack Pro supports more test runners (not only in Ruby).
Co-Founder & Software Engineer | Knapsack