A city permitting portal must wake the intake service only when a payment clears, without a nightly batch job polling a database. Which application pattern should the developers implement?
Select an answer to reveal the explanation.
Short Explanation
Picture a doorbell instead of someone walking the hallway every hour checking if the package arrived. When payment clears, publish an event and let intake wake only then — no nightly database poll. That is the event-driven pattern the portal needs.
Full Explanation
Event-driven applications emit domain events when something meaningful happens, and consumers react asynchronously without polling. A nightly monolith scan couples latency and load to the batch window and wastes work on unpaid rows. Synchronous waits and shared in-process caches add tight coupling and scaling fragility. Publishing a payment-cleared event (for example through EventBridge, SNS, or SQS) lets the intake service scale independently and stay idle until work arrives.