basic-rails/app/controllers/application_controller.rb

class ApplicationController < ActionController::Base
  MAX_DURATION_TO_COMPLETE_IN_SECONDS = 3

  around_action do |_, action|
    start = Process.clock_gettime(Process::CLOCK_MONOTONIC)
    begin
      action.call
    ensure
      duration = Process.clock_gettime(Process::CLOCK_MONOTONIC) - start
      if duration > MAX_DURATION_TO_COMPLETE_IN_SECONDS
        logger.warn("processing took too long to complete, please review your code as asynchronous job!", duration: duration * 1_000)
      end
    end
  end
end