Application performance is always a concern when building in the modern, competitive web and mobile space. At Scout, it’s why we created application performance monitoring tools in the first place. That said, there are steps you can take to build a more performant application. If you are using Ruby on Rails, caching might be one of the best tools on your belt to build a better application. The idea behind caching in Rails is to serve thousands of concurrent users on a single server with a single database attached. Let’s take a look at some of the benefits caching can provide.