AZ-900 Describe Azure architecture and services Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✗

  Azure Service Bus

  Why it's wrong here

  Azure Service Bus is a brokered messaging service designed for reliable queue-based and publish-subscribe messaging. It delivers discrete business commands or data packets with features like sessions, transactions, and competing consumers. Because it isn't wired as an event-routing plane for Azure resource state changes, it would require custom polling or manual integration to react to lifecycle events, whereas Event Grid automatically pushes those state-change events to subscribed handlers.

• ✓

  Azure Event Grid

  Why this is correct

  Azure Event Grid is the correct answer because it is the Azure-native event-routing backplane for reactive workloads. It ingests discrete state-change events from Azure resources and custom sources (via topics) and pushes them to subscribers such as Azure Functions, Logic Apps, or webhooks with server-side retry and dead-lettering. Its extremely low latency (typically sub-second) and built-in filtering make it ideal for serverless event-driven integrations that need to act immediately on changes like blob creation or VM status.

• ✗

  Azure Event Hubs

  Why it's wrong here

  Azure Event Hubs is a high-throughput telemetry ingestion platform built for streaming millions of events per second. Unlike Event Grid, it does not push individual state-change events to handlers; instead, it buffers events in partitions and relies on consumers to read them in sequence for analytics, logging, or batch processing. To react to a resource state change, you would need additional logic (e.g., Stream Analytics or a function) to poll and interpret the stream, which adds latency and complexity that Event Grid's push-based routing avoids.

• ✗

  Azure Monitor Alerts

  Why it's wrong here

  Azure Monitor Alerts is a monitoring and notification engine that proactively detects operational conditions—such as metric thresholds, log search results, or activity log entries—and notifies responders or triggers action groups (email, SMS, webhook). While an activity log alert can catch some Azure resource changes, that capability is limited to rule-matching and human/team notification rather than the flexible, low-latency event routing to automated handlers that Event Grid provides. It is a reactive diagnostic tool, not a purpose-built event distribution fabric for serverless workflows.