From Azure Functions to AWS Lambda: A .NET Developer’s Migration Playbook

This article provides a seven-phase migration playbook for .NET developers transitioning Azure Functions workloads to AWS Lambda, with code examples and best practices.

• Phase 1: Catalog Azure Functions triggers, bindings, dependencies, and configuration to establish migration scope
• Phase 2: Map Azure concepts to AWS equivalents (HTTP triggers to API Gateway, Service Bus to SQS, Blob Storage to S3, Durable Functions to Step Functions)
• Phase 3: Migrate C# code using Lambda Annotations framework for attribute-driven handlers and dependency injection
• Phase 4: Define infrastructure declaratively with AWS SAM or Terraform, with source generator syncing code to IaC
• Phase 5: Validate locally with SAM CLI and test with xUnit before cloud deployment
• Phase 6: Deploy via CI/CD with GitHub Actions; shift traffic incrementally using Lambda aliases and canary releases
• Phase 7: Optimize for cost (Graviton2 arm64 offers 34% better price-performance), latency (SnapStart for sub-second cold starts), and observability
• Lambda Annotations framework provides comparable attribute-driven model to Azure Functions with built-in DI and middleware support
• IAM execution roles replace Managed Identity; Secrets Manager/Parameter Store replace Key Vault; CloudWatch/X-Ray replace Application Insights

The playbook enables .NET teams to systematically migrate serverless workloads from Azure to AWS with reduced risk, improved cost-performance, and operational excellence through structured phases and concrete examples.