How to Write Fast Code in Ruby on Rails

At Shopify, we use Ruby on Rails for most of our projects. For both Rails and Ruby, there exists a healthy amount of stigma toward performance. You’ll often find examples of individuals (and entire companies) drifting away from Rails in favor of something better. On the other hand, there are many who have embraced Ruby on Rails and found success, even at our scale, processing millions of requests per minute (RPM).Part of Shopify’s success with Ruby on Rails is an emphasis on writing fast code. But, how do you really write fast code? Largely, that’s context sensitive to the problem you’re trying to solve. Let’s talk about a few ways to start writing faster code in Active Record, Rails, and Ruby.