Connect to and consume Azure services and third-party services
Integration services and when to use each
API Management fronts APIs: products and subscriptions (keys), policies evaluated in order at inbound/outbound/backend/on-error, rate-limit and quota policies, JWT validation, response caching, and versioning. Policies are XML, and the scope where you define them (global, product, API, operation) determines precedence.
Event Grid handles discrete, reactive events ("blob created", "resource changed") with push delivery, filters, retries, and dead-lettering; the subscriber must complete a validation handshake. Event Hubs is high-throughput streaming with partitions, consumer groups, and checkpointing - telemetry pipelines. Service Bus is brokered messaging with queues and topics/subscriptions, peek-lock by default where you Complete, Abandon, or DeadLetter, sessions for ordered FIFO handling, duplicate detection, scheduled messages, and dead-letter queues.
Selecting the wrong one is the most common trap: reactive event → Event Grid; millions of streaming events → Event Hubs; business message needing ordering or transactions → Service Bus.
Connecting: use SDKs or Functions bindings, authenticate with managed identity where supported, and wrap HTTP calls in retries with backoff. Logic Apps provides hundreds of connectors and triggers for third-party SaaS with no code. Microsoft Graph is the REST API for Entra ID and Microsoft 365 data, using the same scopes/roles model.
Traps
Expecting Event Grid to guarantee ordering or exactly-once delivery; forgetting to complete a Service Bus message so it reappears after the lock expires; expecting a topic to deliver without a subscription; using Event Hubs for request/response workflows.
Worked example
Orders for one customer must process in order: use a Service Bus queue with sessions keyed by customer ID, plus duplicate detection.
Rule of thumb
Match the service to message semantics - event, stream, or command - not to throughput alone.