Design a Customer Onboarding Pipeline

To design a robust onboarding pipeline, I would start by modeling the process as a finite state machine. Each customer journey moves through distinct states: Pending, Verified, Provisioning, Active, or Failed. We would persist these states in a database with optimistic locking to ensure that concurrent requests do not corrupt the workflow. For the orchestration layer, I would use a message broker like Kafka. When a new user signs up, an event is published to a topic. A consumer service reads this event, validates the input, and updates the state machine to 'Verified.' If verification fails, it transitions to 'Failed' and notifies the support team. Crucially, we must handle external dependencies, such as calling a credit card processor or provisioning a cloud environment. I would wrap these calls in a retry mechanism with exponential backoff. If a dependency fails permanently, the state machine should pause and alert an operator rather than failing the entire customer record immediately. This ensures that transient network issues don't cause permanent data loss. Finally, every state transition must be logged immutably for audit trails, which is critical for enterprise compliance standards expected at companies like Salesforce.