Rails engine from Honey Badger for email campaigns. Provides a clean `step :welcome` / `wait 1.day` DSL where waits are implemented via Active Job's `wait:` option. Cheddar Payments evaluated it for general workflows but hit limitations: campaign classes can't call their own methods from steps, campaign identity isn't directly queryable, mid-campaign interruption is hard, and internally it relies on heavy Postgres-specific queries that Julik found 'too clever for its own good'. Its API shape inspired Geneva Drive.