Top 10 ASP.NET Developer Interview Questions & Answers in 2024

1. Explain the differences between ASP.NET Web Forms and ASP.NET MVC.

ASP.NET Web Forms and ASP.NET MVC are two web application frameworks for building dynamic web pages. Web Forms follows the event-driven model with server-side controls, while MVC is based on the Model-View-Controller pattern, offering more control over the HTML markup and separation of concerns.

2. Describe the purpose of the ASP.NET Core framework and its advantages over traditional ASP.NET.

ASP.NET Core is a cross-platform, high-performance framework for building modern, cloud-based, and internet-connected applications. It is an open-source and modular framework that enables cross-platform development, microservices architecture, and improved performance compared to traditional ASP.NET.

3. How does ASP.NET Core handle dependency injection, and what are the benefits?

ASP.NET Core features a built-in dependency injection (DI) system that provides a consistent way to manage object dependencies throughout an application. DI promotes modular, maintainable code, and it facilitates unit testing. Developers can register and resolve services through the built-in container, improving code organization and testability.

4. Explain the role of middleware in ASP.NET Core and provide an example.

Middleware in ASP.NET Core is software components that are executed in the request/response pipeline. They handle specific aspects of the request, such as authentication, logging, or routing. An example is the 'UseAuthentication' middleware, which enables authentication services in the application.

5. Discuss the differences between cookie-based authentication and token-based authentication in ASP.NET.

Cookie-based authentication stores user information in a browser cookie, while token-based authentication involves issuing a token to the client. Token-based authentication is often preferred for modern applications and APIs, providing scalability, statelessness, and ease of integration with other platforms.

6. How can you improve the performance of an ASP.NET application?

Performance optimization in ASP.NET can involve various strategies, such as:

• Caching: Use output caching, data caching, and content delivery networks (CDNs) to reduce server load.
• Asynchronous Programming: Implement asynchronous methods to improve responsiveness.
• Minification and Bundling: Minify and bundle static resources like JavaScript and CSS.
• Compression: Enable gzip or Brotli compression for reducing data transfer.

7. Explain the concept of Razor Pages in ASP.NET Core.

Razor Pages is a lightweight web page framework in ASP.NET Core that makes page-focused scenarios more productive. It allows developers to define a page model (similar to MVC) and a Razor markup file in a single file, promoting simplicity and code organization for specific views.

8. How does ASP.NET Core support cross-site request forgery (CSRF) protection?

ASP.NET Core provides built-in CSRF protection through anti-forgery tokens. Developers can use the 'ValidateAntiForgeryToken' attribute on controllers or Razor Pages to ensure that requests include a valid anti-forgery token. This helps prevent unauthorized requests to the application.

9. Discuss the benefits of using the Entity Framework in ASP.NET Core for database access.

Entity Framework is an Object-Relational Mapping (ORM) framework that simplifies database access in ASP.NET Core. Benefits include:

• Abstraction: Developers work with objects in code rather than raw SQL.
• Portability: Supports multiple database providers.
• Migration: Simplifies database schema changes through code-first migrations.

10. Explain the role of the ASP.NET Core Identity framework and its features.

ASP.NET Core Identity is a membership system that adds login functionality to ASP.NET Core applications. It includes features such as user registration, password recovery, and role-based authorization. It provides a secure and extensible way to manage user authentication and authorization in applications.