Microsoft's latest major release in the .NET ecosystem, .NET 9, brings significant performance gains, new APIs, and modernized tooling to developers worldwide. At BUZ Yazilim, we've thoroughly evaluated how this release can add value to our projects and clients.
Performance Improvements
The most striking aspect of .NET 9 is its remarkable progress in performance:
JIT Compiler Updates
- Loop optimizations: Expanded automatic vectorization support in loops
- Profile-guided optimization (PGO): Enabled by default and made smarter
- Inlining improvements: More aggressive inlining decisions reducing method call overhead
- Arm64 optimizations: Significant speed gains on Apple Silicon and ARM-based servers
Ahead-of-Time (AOT) Compilation
Native AOT support has reached maturity with .NET 9:
- Compilation time reduced by 30%
- Generated binary sizes are smaller
- Full AOT support for ASP.NET Core minimal APIs
- Improved trimming compatibility
A minimal API application compiled with AOT in .NET 9 stands out with a binary size under 5 MB and startup times measured in milliseconds.
ASP.NET Core 9 Updates
Significant updates are available on the web development side:
Minimal API Enhancements
- OpenAPI support: Built-in Swagger/OpenAPI documentation
- Validation: Native validation support in endpoint filters
- Dependency injection: More flexible service resolution with keyed services
- Rate limiting: More granular rate limiting policies
Blazor Updates
- Easier switching between Blazor Server and WebAssembly
- Page-level render mode selection
- Improved JavaScript interop performance
- SEO-friendly pages with static server-side rendering (SSR)
SignalR Improvements
- Strengthened automatic reconnection mechanism
- Native AOT support added
- More efficient protocol options
Entity Framework Core 9
Innovations in the database access layer:
- LINQ query improvements: More efficient SQL output
- Bulk update and delete: Performance gains in
ExecuteUpdateandExecuteDelete - Complex type support: Enhanced support for value objects
- Migration tools: More reliable schema management
- Cosmos DB provider: Deeper integration with Azure Cosmos DB
Container and Cloud Support
.NET 9 is optimized for cloud-native applications:
Container Improvements
- Default Docker images are smaller
- Multi-platform container support (linux/amd64, linux/arm64)
- Simplified distributed application management with .NET Aspire
Observability
- Deepened OpenTelemetry integration
- Enriched metrics and tracing APIs
- New endpoints for health checks
Our Assessment at BUZ Yazilim
.NET 9 offers serious advantages for enterprise projects, particularly with its performance and AOT compilation improvements. Our recommendations for clients:
- New projects should consider starting directly with .NET 9
- Existing .NET 8 LTS projects should be tested in non-critical environments first
- Projects with performance bottlenecks should evaluate AOT compilation
- Microservice architectures should leverage Aspire and container improvements
.NET 9 is a tangible demonstration of Microsoft's performance-focused approach. As with every release, testing in real projects and evaluating the results remains the healthiest approach.
Conclusion
.NET 9 empowers developers and businesses to build faster, more efficient, and more scalable applications. At BUZ Yazilim, we are actively incorporating the capabilities of this new release into our projects. If you want to modernize your project with .NET 9 or start a new one, get in touch with us.