We consider the problem of churn prediction in real-time. Because of the batch mode of inference generation, the traditional methods can only support retention campaigns with offline interventions, e.g., test messages, emails or static in-product nudges. Other recent works in real-time churn predictions do not assess the cost to accuracy trade-off to deploy such models in production. In this paper we present RICON, a flexible, cost-effective and robust machine learning system to predict customer churn propensities in real-time using clickstream data. In addition to churn propensity prediction, RICON provides insights based on product usage intelligence. Through application on a real big data of QBO Advanced customers we showcase how RICON has achieved a top decile lift of 2.68 in the presence of strong class imbalance. Moreover, we execute an extensive comparative study to justify our modeling choices for RICON. Finally, we mention how RICON can be integrated with intervention platforms within Intuit to run large-scale retention campaigns with real-time in-product contextual helps.