<!-- Please complete the template below as best as you can. Make sure to check if this issue has already been raised by someone else first to avoid duplication. For each section below, please add screenshots or links or anything that may help visual learners understand the problem better, even if this takes you an extra minute or two this is a great help to some folks. https://www.learning-styles-online.com/style/visual-spatial/ --> ### Problem Prometheus monitoring preload the Rails app too early: 1. Rails app boots and invokes the `after_initialize` callback [here](https://gitlab.com/gitlab-org/customers-gitlab-com/-/blob/main/config/application.rb#L80) to configure Prometheus. 1. Prometheus client tries to get all jobs that inherit the `ApplicationJob` by using the `ApplicationJob.descendants` but this returns an empty array because we are in the middle of booting. 2. To get all jobs correctly there is one line above `Rails.application.eager_load!` that makes jobs available. The `Rails.application.eager_load!` preloads all classes and modules for our Rails application and this thing was OK in Rails < 6 but such a thing has known [limitations in newer Rails versions](https://github.com/rails/rails/issues/37006). In our case, new Rails 7.1 defaults are never applied because attempting to configure already configured values does nothing. **TL;DR:** We preconfigure the Rails internals before all initializers. The worst part here is that this could also affect other parts of our application where we attempt to configure a behavior but in reality it never gets configured to the desired value or does that too late. For instance, recently we enabled [the generation of `secure_token` during initialization call](https://gitlab.com/gitlab-org/customers-gitlab-com/-/merge_requests/11054): ``` [1] [payment_app][development] pry(main)> CloudActivation.new.activation_code nil ``` It's `nil` but it shouldn't be. Why? Because the new setting in https://gitlab.com/gitlab-org/customers-gitlab-com/-/blob/c3e969ec9b7f2a7593dcd7c737fe6612a2c0a75f/config/initializers/new_framework_defaults_7_1.rb configures it too late. To configure it properly we need to remove the `Rails.application.eager_load!`: ``` [1] [payment_app][development] pry(main)> CloudActivation.new.activation_code "An9LZKacjjPvM1WkQhTdBkSp" ``` But removing that line breaks the `job_endpoints_and_attributes` method because `ApplicationJob.descendants` returns an empty array now. ### Proposal <!-- Consult with `@gitlab-com/business-technology/enterprise-apps/zuora-architects` on the ~"Enterprise Applications" team if Zuora business logic is involved. --> ### How will we measure success?