Event-driven integration architecture synchronizing bookings between OTA platforms and property management systems (Guesty, Hostaway, Hostfully) using asynchronous message queues. RabbitMQ queues distribute booking events to Celery workers, which authenticate via Credential Store and route requests through PMS-specific adapters to external providers. The system implements five phases: OTA-to-PMS booking push, async worker processing with exponential backoff retry logic, inbound PMS webhook handling, scheduled listing/calendar polling, and conflict detection with manual review flagging. Fork this sequence diagram on Diagrams.so to customize retry policies, add PMS providers, or adapt the integration microservice pattern for your hospitality tech stack.