etl.rb

class Etl < ProcessCommand
  def initialize(params)
    # init if required
  end

  def call!
   # call dangerous thing here
  end
end

my_controller.rb

# Handle exception in controller
# Just let it fail
class Controller < ApplicationController
  def index
    MyEtl.call!
    render 'everything_is_ok'
  end
end

class ApplicationController
  rescue_from ProcessError, :with => :error_render_method

  def error_render_method
    render 'everything_is_not_ok'
  end
end

process_command.rb

class ProcessCommand
  def call!(*params)
    new(*params).call!
  rescue Exception => e
    save_and_or_log(e, params)
    raise ProcessError
  end

  def save_and_or_log(exception, params)
    # implement standard way to track exception
    # * logs
    # * tracker
    # * ticket creation
    # * ...
  end
end