Creating boundaries and pushing for objects to be context-free (or at least as low context) goes a long way. Here is an example of the kind of background jobs/workers I tend to write in Ruby/Ruby on Rails apps. This particular example is pulled straight from the http://brewdega.com source code.

import_match_job.rb

require 'sidekiq'

module Import
  class MatchJob
    include Sidekiq::Worker

    attr_reader :agent, :ledgers

    # A facade for consumers, keeping them divorced from the Sidekiq API
    def self.match(import_ledger)
      job_id = perform_async(import_ledger.id)
      import_ledger.attach_job(job_id)
    end

    # In production, this results in the collaborators being these real objects,
    # but in tests I inject my own, stubbed, collaborators. Easy peasy!
    def initialize(ledgers: Ledger, agent: Agent)
      @ledgers = ledgers
      @agent = agent
    end

    def perform(import_ledger_id)
      ledger = ledgers.find(import_ledger_id)
      agent.match(ledger) # All of the real work is delegated to `Import::Agent`!
    end
  end
end

NOTE: The comments are not in the real source, I added them here to provide some insight into my aesthetic.