.NET applications represent a significant portion of enterprise workloads. Modernizing .NET to AWS unlocks cost savings through Linux migration, improved scalability with containers and serverless, and reduced operational burden with managed services.
Why Modernize .NET to AWS?
Organizations modernize .NET applications to:
- Reduce Windows licensing costs: Migrate to .NET on Linux for 40%+ savings
- Improve scalability: Containers and Lambda scale automatically
- Accelerate development: Modern .NET and cloud-native patterns speed delivery
- Exit end-of-life platforms: .NET Framework 4.x reaches extended support limits
- Enable DevOps: Containerization enables CI/CD and infrastructure as code
.NET Modernization Outcomes
| Challenge | AWS Outcome |
|---|---|
| Windows Server licensing | Linux containers: 40% cost reduction |
| Manual scaling | Auto-scaling with ECS/EKS/Lambda |
| .NET Framework lock-in | .NET 6/7/8 on Linux |
| Long deployment cycles | Container-based CI/CD |
| IIS management overhead | Managed container orchestration |
Modernization Paths
Path 1: Rehost on Windows EC2
Lift and shift with minimal changes.
When to use:
- Tight deadlines
- Dependencies on Windows-specific features
- Low modernization ROI applications
AWS services: EC2 Windows, EBS, RDS SQL Server
Path 2: Replatform to Containers
Containerize existing .NET applications.
When to use:
- Applications compatible with .NET Core/.NET 5+
- Teams ready for container operations
- Want consistent deployment across environments
AWS services: ECS, EKS, Fargate, ECR
Path 3: Migrate to Linux
Port .NET Framework to .NET 6+ on Linux.
When to use:
- Reducing Windows licensing is a priority
- Applications are good candidates for .NET upgrade
- Long-term platform investment
AWS services: ECS on Linux, Lambda, EC2 Linux
Path 4: Refactor to Serverless
Decompose into Lambda functions and managed services.
When to use:
- Variable workloads with cost optimization priority
- Event-driven architectures
- New development alongside migration
AWS services: Lambda, API Gateway, DynamoDB, SQS
.NET Framework to .NET 6+ Migration
Moving from .NET Framework to modern .NET unlocks Linux deployment:
AWS Porting Assistant for .NET
Analyzes .NET Framework applications for .NET Core compatibility:
- Compatibility assessment: Identifies incompatible APIs and NuGet packages
- Porting recommendations: Suggests replacements and workarounds
- Effort estimation: Scores applications by porting complexity
- Automated updates: Converts project files and common patterns
Migration Steps
- Assessment: Run Porting Assistant to identify compatibility
- Dependencies: Update NuGet packages to .NET Standard/.NET 6+ versions
- Code changes: Replace Windows-specific APIs with cross-platform alternatives
- Testing: Validate functionality on Linux
- Deployment: Deploy to ECS/EKS on Linux or Lambda
Common Compatibility Issues
| .NET Framework Feature | .NET 6+ Alternative |
|---|---|
| WCF Services | gRPC or REST APIs |
| Windows Registry | AWS Systems Manager Parameter Store |
| Windows Services | Background services in containers |
| System.Web | ASP.NET Core |
| Windows Authentication | AWS IAM / Cognito |
Containerizing .NET Applications
Windows Containers
Run .NET Framework applications in Windows containers:
- Pros: Minimal code changes, familiar Windows environment
- Cons: Larger images, Windows licensing still applies
- Use when: Can’t migrate to .NET 6+ yet
Linux Containers
Run .NET 6+ applications in Linux containers:
- Pros: Smaller images, no Windows licensing, faster startup
- Cons: Requires .NET Framework → .NET 6+ migration
- Use when: Application can be ported to modern .NET
Container Services
| Service | Best For |
|---|---|
| Amazon ECS | Teams new to containers, deep AWS integration |
| Amazon EKS | Kubernetes expertise, multi-cloud portability |
| AWS Fargate | Serverless containers, no infrastructure management |
.NET on Lambda
AWS Lambda supports .NET natively:
Supported Runtimes
- .NET 6 (LTS)
- .NET 8 (LTS)
- Custom runtime for other versions
Lambda Patterns for .NET
- ASP.NET Core on Lambda: Run web APIs serverlessly with Amazon.Lambda.AspNetCoreServer
- Function handlers: Individual functions for specific operations
- Container images: Package .NET Lambda as Docker containers
Benefits
- Pay only for execution time
- Automatic scaling from zero to thousands of concurrent requests
- No server management
- Native integration with AWS services
Database Considerations
.NET applications often use SQL Server. Options on AWS:
| Option | When to Use |
|---|---|
| RDS SQL Server | Minimal changes, managed operations |
| Aurora PostgreSQL | Cost optimization, willing to update data access |
| Aurora MySQL | MySQL expertise, simpler migrations |
| DynamoDB | NoSQL patterns, serverless integration |
See Oracle to AWS for guidance on migrating Oracle backends.
Case Study: ASP.NET to EKS
An insurance company modernized their ASP.NET portfolio to AWS.
Before:
- 50 ASP.NET applications on Windows Server 2012
- IIS management across 30 servers
- 4-week deployment cycles
- $400K annual Windows licensing
Modernization:
- Ported to .NET 6 on Linux
- Containerized and deployed to EKS
- Implemented GitOps with ArgoCD
- Migrated SQL Server to Aurora PostgreSQL
Results:
- 55% infrastructure cost reduction
- Deployment time: 4 weeks → 2 hours
- Auto-scaling handles traffic spikes
- Zero Windows Server licensing
Getting Started
Our free assessment analyzes your .NET portfolio:
- Application inventory with modernization scores
- Porting Assistant analysis for .NET Framework apps
- Recommended path per application
- Cost projection comparing Windows vs. Linux
Related Resources
- Application Modernization to AWS — Complete modernization guide
- Refactor to Serverless — Lambda patterns for .NET
- Replatform Migration — Container strategies