Building a Serverless Architecture (Functions + Event Grid)

Category: Cloud Architecture

Architecture diagram

High-level view of the main components and data/control flows.

Low-level architecture diagram (Visio-style)

Implementation view (networking, security, ops). Click to open full size.

Low-level architecture details

Step-by-step implementation

Step 1/6

Define triggers, throughput, and idempotency

• Choose triggers (Event Grid, Service Bus, HTTP).
• Design idempotency keys to avoid duplicate processing.
• Choose hosting plan (Consumption/Premium).

Validation checklist

• Stakeholders have signed off the scope, SLAs, and data/security requirements.
• You have documented naming standards, environments, and ownership (RACI).

Step 2/6

Provision Function App and supporting services

• Create Function App (Linux recommended) and Storage account.
• Enable managed identity.
• Set app settings via IaC.

Validation checklist

• Deployment completed; smoke tests passed; rollback plan confirmed.

Step 3/6

Implement event routing

• Create Event Grid topic/subscriptions.
• Filter events by subject/type.
• Configure dead-letter destination for failed deliveries.

Validation checklist

• Connections/authentication succeed and test messages/records flow through.
• Retries/DLQ/error handling are configured and validated with a forced failure.

Step 4/6

Secure endpoints and secrets

• Use private endpoints and VNet integration where needed.
• Store secrets in Key Vault and use references.
• Use JWT validation for HTTP triggers.

Validation checklist

• Security baseline applied (Defender/Policy/WAF/Firewall rules as applicable).
• No public endpoints unless explicitly approved; private endpoints verified where applicable.
• Alerts are configured for high-risk events.

Step 5/6

Observability

• Enable Application Insights.
• Track function failures and retries.
• Create dashboards and alerts for queue backlog.

Validation checklist

• Logs and metrics are flowing (check Log Analytics / Monitor).
• Alerts trigger correctly (test alert path to email/Teams/ITSM).

Step 6/6

Testing and resiliency

• Unit test handlers; integration test via test topic.
• Chaos test: drop downstream dependency, validate retries/DLQ.
• Document runbooks for DLQ replay.

Validation checklist

• UAT completed with representative users and scenarios.
• Performance meets baseline; issues tracked and remediated.

Video tutorials

• Azure Friday playlist (search for Azure Functions / Event Grid)
• Azure Videos (Serverless)

References

• Azure Functions documentation
• Event Grid documentation
• Durable Functions