ASP.NET Core Tutorial
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Tutorials ASP.NET Core Tutorial

.NET 8 and .NET 9 Features — Complete Guide

.NET 8 and .NET 9 Features — Complete Guide: free step-by-step lesson with examples, common mistakes, and interview tips — part of ASP.NET Core Tutorial on Toolliyo Academy.

8 min read Updated 6/25/2026
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ASP.NET Core Tutorial (ShopNest) · Lesson 79 of 100

.NET 8 and .NET 9 Features

Beginner ✓ → Intermediate ✓ → Advanced ✓ → Professional

Professional · 4 — Real projects · ~25 min read · Module 8: Deploy & Cloud

Introduction

Professional project lesson: .NET 8 and .NET 9 Features. You will put together API, data, and security like a portfolio app. Build one piece at a time — do not rush. .NET 8 and .NET 9 Features covers shipping ASP.NET Core to IIS, Docker, or Azure. An app only on localhost does not help your portfolio — deploy at least one demo.

An app on your laptop is not finished until it runs on a server others can reach.

When will you use this?

Use when you are ready to put the app online for users or employers to try.

  • Publishing means copying your built app to IIS, Docker, or Azure App Service.
  • CI/CD runs dotnet test and dotnet publish automatically on every git push.

Real-world: Freshdesk-style ticket API

The Customer support team building Freshdesk-style ticket API uses .NET 8 and .NET 9 Features to use latest performance and language improvements. support agents never see the C# code — they just get a fast, reliable ticket queue and reply endpoints.

Production-style code

dotnet publish -c Release -o ./publish
# Deploy publish folder to server or container

What happens in production: In Freshdesk-style ticket API, getting .NET 8 and .NET 9 Features right means support agents trust the ticket queue and reply endpoints every day.

Lesson example (start here)

Copy this smaller example first. Once it works, compare it with the real-world code above.

dotnet publish -c Release -o ./publish
# Deploy publish folder to server or container

Line-by-line walkthrough

CodeWhat it means
dotnet publish -c Release -o ./publishPart of the .NET 8 and .NET 9 Features example — read it together with the lines before and after.
# Deploy publish folder to server or containerComment — notes for humans; the compiler ignores it.

How it works (big picture)

  • Study the example line by line.
  • Each part connects to .NET 8 and .NET 9 Features.
  • Edit one line, save, run dotnet run, and see what changes.

Do this on your computer

  1. Run dotnet publish locally.
  2. Follow the lesson deploy steps for your target.
  3. Open the live URL and test one API or page.
  4. Read the real-world section and name which part of the app uses this topic.
  5. Run the example locally with dotnet run and confirm the same behavior.
  6. Change one value in the example (route, text, or connection string) and predict what will happen before you save.

Experiments — try changing this

  • Change a string or route in the example and save — watch the browser or Swagger response update.
  • Break the code on purpose (remove a semicolon), read the error message, then fix it.

Remember

You learned what .NET 8 and .NET 9 Features is and when to use it in ShopNest. Practice by changing the example yourself. Use the Next link when you can explain it in your own words.

Common questions

What is .NET 8 and .NET 9 Features?

.NET 8 and .NET 9 Features is explained in the introduction above — read it in plain language first.

How long should I spend on .NET 8 and .NET 9 Features?

Until you can explain it in your own words and run the example without looking at the answer. Beginners often need 30–60 minutes per new concept; setup lessons may take one afternoon.

What if I get stuck on .NET 8 and .NET 9 Features?

Re-read the line-by-line walkthrough, check the terminal for red errors, and compare your code character-by-character with the example. Search the exact error text — someone else had it too.

Where is .NET 8 and .NET 9 Features used in real jobs?

See the real-world section above — the same pattern appears in LMS, banking, e-commerce, and SaaS backends. Interviewers ask you to explain it using one concrete example.

ASP.NET Core Tutorial
Course syllabus
Start Here ASP.NET Core Complete Beginner's Guide
Module 1: Introduction & Setup Introduction to ASP.NET Core — Complete Guide ASP.NET Core Ecosystem — Complete Guide ASP.NET Core Architecture — Complete Guide Installing .NET SDK — Complete Guide Installing Visual Studio — Complete Guide VS Code Setup — Complete Guide ASP.NET Core Project Structure — Complete Guide The .csproj File — Complete Guide Program.cs Explained — Complete Guide Launch Settings and Configuration — Complete Guide
Module 2: MVC Fundamentals Controllers and Actions — Complete Guide Routing — Complete Guide Models and ViewModels — Complete Guide Razor Views — Complete Guide Layouts and Partial Views — Complete Guide Tag Helpers — Complete Guide Model Binding — Complete Guide Data Annotations Validation — Complete Guide Static Files Middleware — Complete Guide MVC Architecture — Complete Guide
Module 3: Services & Pipeline Dependency Injection — Complete Guide Middleware Pipeline — Complete Guide appsettings.json — Complete Guide Logging — Complete Guide Exception Handling — Complete Guide Filters — Complete Guide Action Results — Complete Guide JSON APIs in MVC — Complete Guide HttpClient — Complete Guide Enterprise Folder Structure — Complete Guide
Module 4: Entity Framework Core Introduction to EF Core — Complete Guide DbContext — Complete Guide Code First Migrations — Complete Guide CRUD with EF Core — Complete Guide LINQ Queries — Complete Guide Relationships in EF Core — Complete Guide Fluent API — Complete Guide Repository Pattern — Complete Guide Unit of Work — Complete Guide EF Core Performance — Complete Guide
Module 5: Web API & Security Building REST APIs — Complete Guide Swagger and OpenAPI — Complete Guide API Versioning — Complete Guide Authentication Basics — Complete Guide ASP.NET Core Identity — Complete Guide JWT Authentication — Complete Guide Authorization Policies — Complete Guide CORS — Complete Guide HTTPS and Data Protection — Complete Guide Input Validation — Complete Guide
Module 6: Advanced Features Minimal APIs — Complete Guide Background Services — Complete Guide Caching — Complete Guide SignalR Basics — Complete Guide File Upload — Complete Guide Health Checks — Complete Guide Rate Limiting — Complete Guide Clean Architecture Intro — Complete Guide CQRS with MediatR — Complete Guide AutoMapper — Complete Guide
Module 7: Testing & Quality Unit Testing with xUnit — Complete Guide Integration Testing — Complete Guide Mocking with Moq — Complete Guide API Testing with Postman — Complete Guide Test-Driven Development — Complete Guide Load Testing Basics — Complete Guide Debugging Techniques — Complete Guide Structured Logging — Complete Guide Error Handling Patterns — Complete Guide Code Quality Tools — Complete Guide
Module 8: Deploy & Cloud Publishing to IIS — Complete Guide Docker for ASP.NET Core — Complete Guide Azure App Service — Complete Guide Azure SQL Database — Complete Guide Secrets Management — Complete Guide GitHub Actions CI/CD — Complete Guide Output Caching — Complete Guide Response Compression — Complete Guide .NET 8 and .NET 9 Features — Complete Guide Production Checklist — Complete Guide
Module 9: Portfolio Projects Blog Application Project — ShopNest Project Student Portal Project — ShopNest Project Job Portal API Project — ShopNest Project E-Commerce API Project — ShopNest Project Inventory System Project — ShopNest Project Task Manager API Project — ShopNest Project Real-Time Chat Project — ShopNest Project Hospital Appointment Project — ShopNest Project Banking Dashboard API Project — ShopNest Project Multi-Tenant SaaS Project — ShopNest Project
Module 10: Professional Topics Microservices Introduction — ShopNest Project Message Queues — ShopNest Project gRPC Basics — ShopNest Project Blazor Server Intro — ShopNest Project GraphQL Basics — ShopNest Project Enterprise API Design — ShopNest Project Performance Tuning — ShopNest Project Security Hardening — ShopNest Project Full-Stack Architecture — ShopNest Project ASP.NET Core Career Roadmap — ShopNest Project
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