Question

A financial services company is building an order-processing system on Azure. Trades for a given customer account must be processed strictly in the order they were submitted, but trades across different accounts can be processed concurrently to maximize throughput. The team wants a managed messaging service and a competing-consumers pattern where multiple worker instances scale out. Which design meets these requirements?

Accepted Answer

Use an Azure Service Bus queue with sessions enabled and set the SessionId to the customer account ID; workers use session receivers.

Answer

Use an Azure Storage queue and have each worker sort messages by timestamp before processing.

Answer

Use an Azure Event Grid topic with a single subscription and event ordering handled by the subscriber.

Answer

Use an Azure Service Bus queue without sessions and rely on the default first-in-first-out delivery across all consumers.