ASP.NET Interview Questions – C# Corner Edition

📘 Table of Contents

1. Introduction

2. Beginner-Level ASP.NET Interview Questions

3. Intermediate ASP.NET Interview Questions

4. Advanced ASP.NET Interview Questions

5. C# Corner-Inspired Real-World ASP.NET Questions

6. Behavioral & System Design Round

7. Best Practices for Cracking ASP.NET Interviews

8. Conclusion

🧠 Introduction

If you’re applying for an ASP.NET Developer role in 2025, you’re entering a highly competitive tech landscape. Companies like Infosys, TCS, Cognizant, and product firms like Zscaler and Adobe regularly assess candidates on ASP.NET, C#, Entity Framework, Web APIs, LINQ, and performance optimization.

This guide compiles the top ASP.NET interview questions, many of which are frequently discussed on C# Corner—a popular .NET developer community.

🟢 Beginner-Level ASP.NET Interview Questions

1. What is ASP.NET?

ASP.NET is an open-source, server-side web-application framework designed for web development to produce dynamic web pages using .NET and C#.

2. What is the difference between ASP.NET Web Forms and MVC?

3. What is the Global.asax file?

This file defines application-level events such as Application_Start, Application_Error, Session_Start, etc.

4. What are the types of Authentication in ASP.NET?

• Windows Authentication

• Forms Authentication

• Passport Authentication

• OAuth/OpenID (in modern ASP.NET Core)

5. What is ViewState?

ViewState preserves data of web controls between postbacks in Web Forms. It stores data in a hidden field on the page.

6. Explain the Page Life Cycle in ASP.NET Web Forms.

1. Page Request

2. Start

3. Initialization

4. Load

5. Postback event handling

6. Rendering

7. Unload

🟡 Intermediate ASP.NET Interview Questions (2–4 Years)

7. Difference between Server.Transfer and Response.Redirect?

• Server.Transfer changes pages on the server without a round-trip.

• Response.Redirect sends an HTTP response to the browser to request another page.

8. What is an HTTP Handler?

An HTTP Handler is the endpoint that handles HTTP requests. For example, you can create a custom handler to serve images dynamically.

9. What is the role of web.config?

Configuration file used to control:

• Authentication

• Session State

• Database connections

• Custom error pages

10. What is the difference between ASP.NET MVC and ASP.NET Core?

11. What is Bundling and Minification?

Used to reduce the number of HTTP requests and size of scripts and CSS by combining and compressing them.

12. What are Razor Views?

Razor is a view engine in ASP.NET MVC and Core that allows mixing of C# code with HTML using @ syntax.

🔴 Advanced ASP.NET Interview Questions (5+ Years)

13. How does ASP.NET Core’s middleware pipeline work?

Middleware components handle requests and responses in a pipeline using the Configure() method in Startup.cs.

14. How do you implement Dependency Injection in ASP.NET Core?

public void ConfigureServices(IServiceCollection services)
{
    services.AddScoped<IMyService, MyService>();
}

Then inject into controller using constructor.

15. What is the difference between AddSingleton, AddScoped, and AddTransient?

16. What are Tag Helpers?

Tag Helpers enable server-side code to create and render HTML elements in Razor pages.

Example:

<environment include="Development">
    <script src="dev.js"></script>
</environment>

17. What is Model Binding?

Model binding maps form values to method parameters in MVC or Razor Pages automatically.

18. Explain Middleware Ordering in ASP.NET Core.

Order of middleware matters. Example:

app.UseRouting();
app.UseAuthentication();
app.UseAuthorization();
app.UseEndpoints(...);

19. What is the difference between TempData, ViewData, and ViewBag?

💬 C# Corner-Inspired Real-World ASP.NET Questions 

20. How do you secure Web APIs in ASP.NET Core?

• Use JWT tokens

• OAuth2 / IdentityServer

• Role-based authorization

• HTTPS

21. How do you handle versioning in ASP.NET Core Web APIs?

• Route-based: /api/v1/controller

• Header-based

• Query string versioning

22. How to optimize performance in large ASP.NET Core apps?

• Response caching

• Compression

• Async/Await

• Load balancers

• Minimize middleware

23. Difference between .NET Framework and .NET 6+?

24. Explain Exception Handling in ASP.NET Core.

Use app.UseExceptionHandler("/Error") middleware or try-catch with logging frameworks like Serilog.

25. What is Kestrel?

Kestrel is the cross-platform web server used in ASP.NET Core apps. It can be run directly or behind IIS/Nginx.

🧩 Behavioral & System Design Questions {#behavioral-aspnet}

26. How do you handle tight deadlines in development?

• Agile practices

• Prioritize critical tasks

• Daily standups

• Reduce tech debt post-deadline

27. Explain how you’ve scaled a .NET application.

• Used Redis for caching

• Horizontal scaling via Docker

• Async DB calls

• CDN for static assets

28. How do you manage team conflicts in a project?

• Active listening

• Bring focus back to goals

• Escalate when needed

🧠 Best Practices for Cracking ASP.NET Interviews 

1. Be hands-on with .NET Core & C# 10+

2. Understand LINQ and async/await deeply

3. Know the evolution: Web Forms → MVC → Core

4. Revise concepts via C# Corner articles

5. Practice with mini projects on GitHub

6. Explain tradeoffs in architecture decisions

7. Prepare system design for Web APIs

📝 Conclusion

The .NET ecosystem continues to evolve rapidly, and ASP.NET remains one of the most in-demand web frameworks in the enterprise space. To ace your next .NET or ASP.NET Core interview:

• Master fundamentals

• Stay updated with C# and .NET versions

• Practice with real-life scenarios from platforms like C# Corner

• Communicate clearly and confidently

✅ Explore More:

• Top 100 SQL Query Interview Questions

• Top 25 HR Round Questions

• Top 10 Behavioral Interview Question