Right now, tweets are sent out on successful release from within the controller. There are a few problems with this, though:
So create an interface for adding callbacks on successful release, but where the user doesn't get an error if any callbacks fail. They should be configurable in the configuration file, and easy to implement. Perhaps use Plack middleware as a model.
Another suggestion from Hitoshi Harada:
In terms of fail tolerant system, I'd suggest MQ. But for customizability of users I don't know which direction should go.