DBOS Pro's subscription management and billing system, launched in April, was developed using DBOS Transact and Stripe to ensure security, reliability, scalability, and maintainability. The system, which comprises less than 500 lines of code, handles customer upgrades through a webhook that manages subscription status updates from Stripe to DBOS Cloud. The developers faced challenges such as ensuring quick webhook responses, event processing completion despite interruptions, and managing duplicate events. These were addressed by implementing a DBOS Transact reliable workflow that automatically resumes after interruptions and uses idempotency keys for event uniqueness. The application is hosted serverlessly on DBOS Cloud, simplifying deployment and scaling, and is available as open-source on GitHub.