I should add that these are just the functional gems for a Rails app. For development and testing, I'll still bring in better_errors, binding_of_caller, factory_bot_rails, rspec_rails, simple_cov and dotenv-rails. These fit my development workflow and makes my life a bit easier as a developer. Other gems which do not require to be in the Gemfile that I still like and use are annotate, brakeman, and bundler-audit.