Integration is one of the trickiest exam areas because Azure offers overlapping services (Service Bus, Event Grid, Event Hubs, Storage Queues, APIM). The exam often tests your ability to choose the right service and pattern for the scenario. This capsule highlights the common pitfalls, best practices, and exam strategies.
Common Pitfalls
1. Confusing Service Bus vs Event Grid vs Event Hubs
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Service Bus → enterprise messaging, transactions, ordering, DLQ.
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Event Grid → lightweight, real-time, event push, fan-out.
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Event Hubs → big data ingestion, telemetry streaming.
Exam Trap: If scenario says “ingest millions of IoT messages/sec” → Event Hubs, not Event Grid.
2. Overlooking Dead-Letter Handling
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Event Grid → dead-letter destination.
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Service Bus → DLQ built-in.
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Many forget that dead-lettering is essential for reliable integrations.
3. Misusing API Management
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Some think APIM provides load balancing.
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Correction: APIM is an API gateway (security, governance, transformation), not a traffic router.
4. Request/Reply vs Async Decoupling
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If real-time confirmation is required → use APIM / direct API call.
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If backend processing can be delayed → use Service Bus queue.
5. Wrong Fan-Out Implementation
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Event Grid = best for fan-out workflows.
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Service Bus Topics = best for reliable fan-out with filtering.
Best Practices
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Choose Service Bus when reliability, ordering, and transactions matter.
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Choose Event Grid for lightweight pub/sub and serverless event-driven apps.
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Choose Event Hubs for high-volume telemetry ingestion.
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Use APIM to secure and publish APIs (OAuth, throttling, transformation).
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Always configure dead-lettering to avoid message loss.
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Implement idempotency in consumers (avoid double-processing).
Quick Recall Table
| Requirement | Best Solution |
|---|---|
| Enterprise messaging with transactions | Service Bus Queue/Topic |
| Pub/Sub with filtering & reliability | Service Bus Topics |
| Lightweight real-time events (Blob upload) | Event Grid |
| Big data telemetry ingestion | Event Hubs |
| Secure and publish APIs | API Management (APIM) |
| Fan-out to multiple independent subscribers | Event Grid or Topics |
| Handle poison/failed messages | Dead-Letter Queue (DLQ) |
| Real-time synchronous request/response | API Management |
Exam Tips
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“Which Azure service supports publish/subscribe with SQL filters?” → Service Bus Topics.
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“Which Azure service is best for IoT telemetry ingestion?” → Event Hubs.
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“Which integration service includes developer portal and API transformation?” → APIM.
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“Which service handles blob upload triggers in real time?” → Event Grid.
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“Which queue service includes built-in DLQ?” → Service Bus.
What to Expect in the Exam
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Direct Q: “Which service enables API security, throttling, and analytics?” → APIM.
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Scenario Q: “E-commerce app must notify multiple downstream services on order placement.” → Pub/Sub with Service Bus Topics.
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Scenario Q: “App must ingest millions of telemetry events for real-time analytics.” → Event Hubs.
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Scenario Q: “Blob upload must trigger virus scan + resize + notification workflows.” → Event Grid fan-out.
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Trick Q: “API Management provides load balancing like Front Door.” → False.