Azure Functions.

Azure Functions is Microsoft's serverless compute offering for code started by HTTP, timers, files, database changes, queues or event streams. Its important convenience is bindings: they connect triggers and Azure services without hand-writing every integration. The difficult work still lives in failure paths, data contracts and operations.

Suitable workloads

Functions suits API endpoints, Blob processing, Service Bus consumers, scheduled cleanup, Event Hubs streams and bounded automation. One function should own a small business responsibility. Long-running processes, human waiting periods and complex state transitions should not disappear into retry loops.

Flex Consumption, Premium or Dedicated

Microsoft recommends Flex Consumption for new event-driven apps: fast scaling, VNet integration and pay-as-you-go billing. Premium keeps instances warm and provides VNet and unlimited execution duration, but costs while ready. Dedicated runs in an existing App Service plan and suits predictable capacity. The choice is about latency, networking and cost, not only a price label.

Handle events reliably

A queue or event trigger can be delivered again. Handlers validate payloads, make idempotent writes and log correlation IDs. Define retry count, stop condition, dead-letter or poison-message route, alert and owner for every trigger. Deliberately test a duplicate message, timeout and unavailable dependency.

Azure Monitor and Application Insights expose latency, failures and traces. They help only when structured events, business metrics and an alert path exist. A green function status does not prove that an invoice, order or data change was processed correctly.

Durable Functions for workflows

Durable Functions adds orchestrator, activity and entity functions. Its runtime manages state, checkpoints, retries and recovery for long-running workflows. This fits a multi-step request with human approval. Orchestrator code has determinism constraints; side effects belong in activities and require tests.

Identity and secrets

Use Managed Identities and smallest RBAC roles instead of long-lived keys. Separate function, storage, queue and production environments. Store secrets in Key Vault or equivalent. Local development with Core Tools is useful, but deployment needs separate configuration, CI/CD and rollback.

Editorial Assessment

Azure Functions is a strong option for Azure-centred event logic. It removes infrastructure, not architecture. Start with one real trigger and a deliberately failing message. Scale the function estate only when idempotency, permissions, monitoring and cost per business outcome are clear.