You are designing a serverless microservices architecture for a new startup. The application needs to handle unpredictable traffic spikes without managing any underlying infrastructure. Which compute service should you use?

You are building an Azure Function that processes orders from an Azure Service Bus queue. The function must ensure that each order is processed exactly once, even if the function crashes mid-processing. Which Service Bus feature guarantees this behavior?

Your Azure Function app needs to store temporary state between multiple function executions as part of a long-running workflow. The workflow includes human approval steps that can pause for days. Which solution should you implement?

You have an Azure Function triggered by a Timer. During load testing you notice that multiple instances of the function run simultaneously, causing duplicate processing. How do you prevent concurrent executions of a timer-triggered function?

You are building an event-driven microservice using Azure Functions. The function must process messages from an Azure Service Bus queue and write results to Azure Cosmos DB. To minimize cold-start latency and ensure the function scales with message volume, which hosting plan and trigger combination is most appropriate?