Mastering .NET Interviews – Part 4: ASP.NET MVC

📌 Series Context: This is the fourth article in the 10‑part series covering the most important areas of .NET interview preparation. In Part 1, we introduced the .NET ecosystem. In Part 2, we covered C# fundamentals. In Part 3, we explored advanced C# features. Now, we'll dive into ASP.NET MVC, one of the most common topics in interviews.

Why ASP.NET MVC?

ASP.NET MVC (Model-View-Controller) revolutionized web development in .NET by introducing a separation of concerns. It allows developers to build scalable, testable, and maintainable web applications. Interviewers often ask about MVC architecture, routing, controllers, views, and filters.

MVC Architecture

Model

• Represents the application's data and business logic.

View

• Handles UI rendering.

Controller

• Manages user requests and responses.

👉 This separation ensures clean code and makes applications easier to test.

Example: Patient Management in MVC

Controller

public class PatientController : Controller
{
    private readonly IPatientService _service;

    public PatientController(IPatientService service)
    {
        _service = service;
    }

    public IActionResult Index()
    {
        var patients = _service.GetAll();
        return View(patients);
    }

    [HttpPost]
    public IActionResult Create(Patient patient)
    {
        _service.Add(patient);
        return RedirectToAction("Index");
    }
}

View (Razor)

@model IEnumerable<HospitalManagement.Models.Patient>

<h2>Patient Records</h2>

<table class="table">
    <thead>
        <tr>
            <th>Name</th>
            <th>Age</th>
            <th>Disease</th>
        </tr>
    </thead>
    <tbody>
    @foreach (var p in Model)
    {
        <tr>
            <td>@p.Name</td>
            <td>@p.Age</td>
            <td>@p.Disease</td>
        </tr>
    }
    </tbody>
</table>

Model

public class Patient
{
    public int Id { get; set; }

    public string Name { get; set; }

    public int Age { get; set; }

    public string Disease { get; set; }
}

Routing

ASP.NET MVC uses routing to map URLs to controller actions.

Example

routes.MapRoute(
    name: "Default",
    url: "{controller}/{action}/{id}",
    defaults: new
    {
        controller = "Home",
        action = "Index",
        id = UrlParameter.Optional
    }
);

👉 Interview Tip: Be ready to explain how routing works and how to customize routes.

Filters

Filters allow cross-cutting concerns such as:

Authorization

[Authorize]

Exception Handling

[HandleError]

Action Filters

[ActionFilter]

Common Interview Questions (Part 4)

• Explain the MVC architecture.

• What is the difference between ViewData, ViewBag, and TempData?

• How does routing work in ASP.NET MVC?

• What are filters and how are they used?

• How do you implement validation in MVC?

Conclusion

In this fourth part, we covered:

• The MVC architecture (Model, View, Controller).

• Example implementation with Patient Management.

• Routing and Filters in ASP.NET MVC.

• Typical interview questions on MVC.

This foundation prepares you for Part 5, where we'll explore ASP.NET Core — the modern, cross-platform successor to MVC.

Summary

ASP.NET MVC follows the Model-View-Controller design pattern, enabling developers to separate application logic, user interface rendering, and request handling into distinct components. Understanding MVC architecture, controllers, views, routing, filters, and common interview questions provides a strong foundation for building maintainable web applications and succeeding in .NET interviews.