APM

APM is useful for finding performance issues.

ScoutAPM

There are many available services that provide APM reporting. ScoutAPM is the chosen one by default. ScoutAPM integrates well with both Ruby on Rails and React applications.

Hosting

ScoutAPM has a plugin for Heroku, so it's possible to set it up for free with just one click from the app's resources widget in Heroku's panel. It is also possible to set up an account directly in ScoutAPM and don't depend on Heroku at all.

Server Configuration

cd server
bundle add scout_apm

Set the SCOUT_KEY environment variable if you did not install via the Heroku plugin.