RubyGems can make it easy to add a feature to a Rails application, but it can also cause headaches down the road. Here I give some tips on researching gems to decide which one to choose, or when to do it from scratch.
Learn how to add performance tests that automate benchmark and profile reports. Here I show how to find the bottlenecks to optimize a page. I also show how to compile Ruby with gcdata to get information about memory usage.
Here I describe each Rack middleware that is included in a Rails app which will give you a better understanding of what a request goes through behind the scenes before it hits your application.
Rack comes with many helpful utilities such as request and response objects, various middleware, and MockRequest for testing. Here I cover all of these while building a Rack app from scratch.