ASP.NET Core

Should you go to .NET 10 LTS or wait for .NET 11? .NET 11 launches on November 10 — the same day .NET 8 and .NET 9 reach end of support. Here’s a practical decision guide. Choose .NET 10 LTS if: - You need long-term support (until November 2028) - Your app is in production or business-critical - You want maximum stability and fewer breaking changes - Your team prefers proven releases over the newest features Consider .NET 11 if: - You want the latest ASP.NET Core features (Runtime Async, better Blazor, OpenAPI 3.2, async validation, etc.) - You’re building a new project or can afford more frequent upgrades - You’re comfortable with STS support - You plan to upgrade again in the next 1–1.5 years anyway Quick recommendation for most teams: Go to .NET 10 LTS now. You get security and support until 2028 with lower risk. You can always move to .NET 11 later if specific features become important. What are you planning to do? Reply with: - ⚡️ — moving to .NET 10 LTS - ❤️ — going straight to .NET 11 - 👌 — staying on current version for now Note: This is a general recommendation based on publicly available information. Always verify the latest support timelines, release status, and breaking changes directly with official Microsoft documentation before making production decisions. Official sources: https://dotnet.microsoft.com/en-us/platform/support/policy https://devblogs.microsoft.com/dotnet/ #dotnet #ASPNETCore #dotnet10 #dotnet11 #Migration #LTS

Common mistakes when upgrading ASP.NET Core projects Moving from .NET 8/9 to .NET 10 is usually smooth, but these issues catch a lot of teams: 1. Outdated package versions Not updating all Microsoft.AspNetCore.* and related packages after changing the TargetFramework. Fix: Run dotnet list package --outdated and upgrade everything consistently. 2. Minimal hosting model assumptions Code that relied on the old Startup.cs pattern or implicit service registrations can break. Fix: Explicitly register services and review Program.cs carefully. 3. Identity and authentication changes Cookie settings, token validation, or passkey-related configuration behaving differently. Fix: Re-test login, logout, and role/claim flows end-to-end. 4. Blazor and static assets Changes in Blazor script loading, base path, or static asset handling. Fix: Verify _framework files, <base href>, and component rendering after upgrade. 5. Configuration and options binding IOptions vs IOptionsSnapshot / IOptionsMonitor differences, or missing configuration sections. Fix: Double-check appsettings binding and hot-reload behavior. 6. Docker and CI images Still using old runtime images (aspnet:8.0 or 9.0). Fix: Update all Dockerfiles and pipeline images to 10.0. 7. Skipping proper testing Only testing “happy path” and missing authorization, file uploads, or background services. Fix: Run full regression tests before production deployment. Most of these are easy to avoid with a structured checklist and good tests. Which of these have you run into during upgrades? #dotnet #ASPNETCore #dotnet10 #Migration #UpgradeTips

5 ASP.NET Core Features Coming in .NET 11 .NET 11 is launching next week (November 10). Here are five ASP.NET Core improvements worth knowing: 1. Runtime Async Async state machines move into the runtime. You get cleaner stack traces, lower overhead, and better performance with almost no code changes. 2. Async Validation (Minimal APIs + Blazor) Validation can now be asynchronous end-to-end. Perfect for checks against a database or external service.

public class UniqueEmailAttribute : AsyncValidationAttribute
{
    protected override async Task<ValidationResult?> IsValidAsync(
        object? value, ValidationContext context)
    {
        // check database / external API
        return ValidationResult.Success;
    }
}

3. OpenAPI 3.2 by Default Better support for binary responses, Server-Sent Events, and more accurate schemas. You can still pin an older version if needed. 4. Blazor Upgrades - Virtualize: Better variable-height support + scroll to item - QuickGrid: URL-based pagination/sorting - New <BasePath /> component - TempData in static SSR - Circuit pause when tab is inactive 5. Native OpenTelemetry Attributes ASP.NET Core now emits standard OpenTelemetry semantic attributes on HTTP server activities out of the box. No extra instrumentation package required for basic tracing. Which of these are you most interested in trying first? #dotnet #ASPNETCore #dotnet11 #Blazor #MinimalAPIs #OpenAPI

.NET 8 and .NET 9 Support Termination in 8 Days — Operational Implications 📅 On November 10, 2026, both .NET 8 (LTS) and .NET 9 (STS) will reach their end-of-support dates simultaneously. Cessation of Services after November 10: - Security patches - Servicing updates - Official technical support from Microsoft Continued Functionality: Existing applications will continue to operate; there is no automatic shutdown on the 11th. However, any vulnerabilities identified after this date will remain unpatched in .NET 8 and .NET 9. For internet-facing applications, systems handling personal data, or environments subject to compliance and security reviews, this presents a significant risk. Recommended Action: Migrate to .NET 10, the current Long-Term Support (LTS) release, which is supported until November 14, 2028. Migration Checklist: - Update the .NET SDK and runtime on local machines and CI environments - Modify the target framework to <TargetFramework>net10.0</TargetFramework> - Update Microsoft.AspNetCore.* and other NuGet packages - Review and address breaking changes (refer to official compatibility documentation) - Execute full regression tests - Update Docker images, hosting environments, and deployment pipelines Note that .NET 11 is also scheduled to launch around the same date as a Standard Term Support (STS) release; however, for most production workloads, .NET 10 LTS remains the safer long-term choice. Official announcement: https://devblogs.microsoft.com/dotnet/dotnet-8-9-end-of-support/ Support policy: https://dotnet.microsoft.com/en-us/platform/support/policy #dotnet #ASPNETCore #dotnet10 #Migration #EndOfSupport

Learn to add a Razor Page for reading and writing data via Entity Framework Core from an existing SQL Server database, reverse-engineered using the EF Power Tools Visual Studio extension.

AWS Transform now converts Azure SDK .NET apps to AWS SDK equivalents. It detects Azure services, maps them to AWS, rewrites code, and validates output. Supported conversions: Azure Functions to Lambda, Blob Storage to S3, Queue Storage to SQS, and Cosmos DB to DynamoDB (preview). Available in 8 regions: US East, Mumbai, Tokyo, Seoul, Sydney, Canada, Frankfurt, London. https://aws.amazon.com/about-aws/whats-new/2026/10/aws-transform-azure-to-aws-code-conversion/

Tuning the default logging providers in ASP.NET Core through configuration https://bartwullems.blogspot.com/2026/10/tuning-default-logging-providers-in.html

For years, APIs have had one primary audience: applications. A frontend calls an endpoint, receives a response, and the developer handles whatever happens next. All of it was from a human user. Now, we have a new player: AI. Instead of simply following predefined application logic, an agent can decide which endpoints to call, determine the order of operations, retry failed requests, and carry out multi-step tasks based on a user's goal. Your API is no longer just serving an application, it may be serving an AI system capable of taking action. Companies like Stripe, Twilio, and Shopify have already launched dedicated Model Context Protocol servers to capture agent-driven traffic. https://blog.elmah.io/designing-apis-for-ai-agents-your-api-has-a-new-user/

OnTheFlySettings - Update your Asp .Net API/App settings without re-start. Zero downtime! https://dev.to/veritassoftware/ontheflysettings-update-your-asp-net-apiapp-settings-without-re-start-zero-downtime-2mj0

NET 11 is presented as a release that “turns performance up to eleven,” delivering hundreds of targeted optimizations across the runtime, JIT, GC, async infrastructure, and core libraries. The article highlights major advances such as deeper devirtualization, smarter inlining, expanded escape analysis, leaner delegate structures, and a redesigned async/await system driven by the JIT rather than the compiler. Together, these improvements reduce allocations, shrink call overhead, streamline async state machines, and unlock faster execution paths—resulting in noticeably better real‑world performance without requiring developers to change their code. https://devblogs.microsoft.com/dotnet/performance-improvements-in-net-11/

If your .NET pods are each using 1–2 GB of RAM, you may be leaving a lot of pod density — and money — on the table. Here are the first things I would look at. https://ardalis.com/top-10-ways-to-reduce-net-memory-usage-in-kubernetes/

In real-world applications, duplicate API requests are more common than many developers expect. Users double-click buttons, mobile apps retry requests automatically, networks fail and resend calls, and background jobs may retry failed operations. https://medium.com/stackademic/how-to-prevent-duplicate-api-requests-in-net-c54e4770da2d

Дьжььь

Bit different from usual ASP.NET stuff, but you might find this interesting. https://youtu.be/JGwFsyyewYc?si=Udwc19INncdm1IOk

Today is 256th day in a year. It's a good reason to celebrate Programmers Days! Happy Coding, guys! 💪