.NET 11 Preview 2 Released: Next-Generation Features Focused on Performance, Cloud and AI

The .NET platform, at the center of Microsoft's developer ecosystem, keeps gaining new capabilities. The eagerly awaited .NET 11 Preview 2 has finally been announced. Rapidly adopted in the software development world and pushing performance higher with every release, .NET raises the bar considerably with this new preview.

With .NET 11 Preview 2, notable improvements have been made across many core areas, including the .NET Runtime, the SDK, the core libraries, ASP.NET Core, Blazor, .NET MAUI, F# and Entity Framework Core. Smaller container images, runtime optimizations and database search features that support AI integrations are among the highlights of this release.

📚 Performance and Flexibility in the Libraries

The core libraries (.NET Libraries) that form the backbone of applications received very important changes that will boost developer productivity and application performance. There is a visible speedup especially in resource-hungry areas such as serialization and mathematical operations:

* Generic GetTypeInfo for System.Text.Json: JSON serialization and deserialization are always among the most critical performance bottlenecks in web API scenarios. The generic GetTypeInfo support added to System.Text.Json in .NET 11 reduces runtime Reflection costs, maximizing type safety and processing speed. * Tar Archive Format Selection: Finer control is now available for TAR formats, which matter for portability between different systems and platforms. Developers can directly choose the spec format they need when creating an archive. * Matrix4x4.GetDeterminant Speedup: Great news for math-heavy applications such as game development, graphics processing and scientific computing. The performance of the GetDeterminant method in the Matrix4x4 struct has been improved by about 15%.

⏱️ Runtime and JIT Optimizations

The real power of a language and framework lies in the runtime performance under the hood. .NET 11 Preview 2 includes important fine-tuning in this lower layer where the application meets the hardware:

* Runtime Async (V2): Asynchronous programming is essential for the responsiveness of modern applications. However, the async/await mechanism creates a state machine and memory allocations behind the scenes. The new async infrastructure (V2) minimizes Task allocations, saving CPU cycles and lightening the memory load of async stacks. * JIT (Just-In-Time) Improvements: The JIT compiler is responsible for producing the most suitable machine code while code executes. Preview 2 brings loop unrolling, smarter inlining and more efficient use of vector instruction sets. * Cached Interface Dispatch: Thanks to this improvement at the virtual machine (VM) level, interface calls are resolved faster. Especially in large enterprise applications that make heavy use of object-oriented design patterns, this means cumulative performance gains at the microsecond level.

🛠️ SDK: Smaller Payloads, Smarter Analyzers

The Software Development Kit (SDK) is the tool developers interact with most throughout the day. The new SDK updates aim to save both bandwidth and disk space:

* Smaller SDK Installers on Linux and macOS: Downloading and installing the SDK quickly matters a lot, especially in CI/CD (Continuous Integration / Continuous Delivery) pipelines. Microsoft has trimmed the SDK installer packages for Linux and macOS, enabling faster downloads and a smaller footprint. * Code Analyzer Improvements: New analyzers are now in place that catch potential bugs more intelligently while you are still writing code and enforce compliance with best-practice guidelines. In addition, new warnings and build targets tighten control over project dependencies.

🌐 ASP.NET Core and Blazor: Cloud-Based Web Development

The ASP.NET Core web application framework has been made more observable and performant on the server side than ever before.

* Native OpenTelemetry Tracing: In modern microservice architectures, monitoring the internal state of applications and the request flows between them is vital. ASP.NET Core now provides OpenTelemetry tracing natively, relying less on external add-ons. This significantly speeds up collecting telemetry data and sending it to cloud dashboards. * TempData Support for Blazor: TempData, commonly used in MVC and Razor Pages projects to carry short-lived data between pages, is finally fully supported in Blazor, which works in an SPA and component-based way. * OpenAPI 3.2.0 Support: The API documentation standards at the heart of RESTful services have been updated. ASP.NET Core projects now work seamlessly with the more modern and detailed OpenAPI 3.2.0 specification. .NET Web Worker Project Template: A new Web Worker* template is available for developing long-running background tasks, message queue consumers (RabbitMQ, Kafka) or periodic cron jobs.

🎁 Entity Framework Core: Hello to AI Workloads

EF Core 11, the database interaction tool (ORM), contains some of the most ambitious and innovative updates in this release:

* LINQ MaxBy and MinBy Support: These LINQ operators, frequently used with C# lists and much loved by developers, can now be translated by EF Core directly into far more optimized SQL queries. * SQL Server DiskANN Vector Indexes and VECTOR_SEARCH(): This is what the AI era has been waiting for! Companies no longer have to rely on external vector databases when storing and searching text/image embedding data in scenarios such as RAG (Retrieval-Augmented Generation). DiskANN vector indexes created on SQL Server can be queried directly through EF Core thanks to the VECTOR_SEARCH() function. This speeds up "Enterprise AI" integrations tremendously! * SQL Server JSON_CONTAINS() and Full-Text Index: JSON_CONTAINS(), which enables deep searches in JSON-typed columns, and full-text indexing capabilities can now be used directly through EF Core.

📱 .NET MAUI: A Seamless Mobile Experience

.NET MAUI, Microsoft's cross-platform app development framework, brings together the mobile and desktop worlds:

* Map Control Improvements: Middleware fixes were made so that it works more smoothly with the native map controls provided by the platforms. * TypedBinding Performance: Data binding, which forms the bridge between the UI and data models (ViewModel), gains a big performance boost thanks to TypedBinding. Reduced use of Reflection has noticeably accelerated list (collection) components on both Android and iOS. * API 24 Requirement for CoreCLR Android: In addition, to make more advanced features available, Android targets now require the device to run at least API 24 (Android 7.0) for CoreCLR apps to work.

📦 Container Images: Smaller and More Secure

Good news for Docker containers, the backbone of modern cloud investments: SDK container image sizes have been reduced by up to 17%.

Smaller images mean they can be pulled from the registry much faster on cloud infrastructure (AWS EKS, Azure AKS, etc.), deployments speed up and cold start times drop. A smaller surface area also helps prevent security vulnerabilities.

Conclusion: .NET 11 Is Coming in Force

.NET 11 Preview 2 is a release aimed at strengthening the backbone of the ecosystem rather than adding language features. Even the mathematical and hardware optimizations in the 15-17% range alone mean considerable energy and cost savings for large server farms around the world. In addition, EF Core's vector search capabilities are a historic step in that they turn AI from an add-on into a natural, integrated capability of the ecosystem. On the road to the stable release, developers will meet a more modern, agile and cloud-native framework in fall 2026.