It is highly recommended you install it for better performance and increased compatibility in certain edge cases (translation: you may be able to get by without installing this, but your mileage may vary; installing this now may save you from a headache later).

we strive to heed upstream's recommendations on how they intend for their software to be consumed.

it is highly encouraged to switch to zeitwerk mode because it is a better autoloader

This meant that we owned both sides of the product implementation. For unit testing on the frontend, we stayed with Angular’s suggestion of Jasmine. For unit testing on the backend, we went with rspec-rails. These worked well since unit tests don’t need to cross technology boundaries.