Top 20 .NET, ASP.NET MVC, SQL Server & Angular Interview Questions with Answers (2025 Guide)

Whether you're preparing for your next interview or brushing up on full-stack development concepts, these frequently asked questions across .NET, ASP.NET MVC, SQL Server, and Angular will help you stand out with clarity and confidence.

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✅ .NET / .NET Core

1. What is the difference between .NET Framework and .NET Core?
.NET Framework is Windows-only, while .NET Core is cross-platform (Windows, Linux, macOS). .NET Core also provides better performance, modular architecture, and support for microservices and cloud-native development. With the introduction of .NET 5+, the ecosystem is unified under .NET (dropping "Core").

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2. What is Dependency Injection in .NET Core?
Dependency Injection (DI) is a design pattern used to achieve Inversion of Control (IoC) between classes and their dependencies. It’s built-in in .NET Core.

services.AddScoped<IMyService, MyService>();

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3. Explain Middleware in ASP.NET Core.
Middleware is software in the request/response pipeline. Each middleware can process the request or pass it to the next.

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

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4. Difference: AddScoped vs AddSingleton vs AddTransient

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5. Role of Program.cs & Startup.cs in .NET 6/7
In .NET 6+, Startup.cs is merged into Program.cs using the Minimal Hosting Model.

var builder = WebApplication.CreateBuilder(args);
var app = builder.Build();

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6. How do you handle configuration & logging in .NET Core?
Use appsettings.json, IConfiguration, and ILogger for config and logging.

builder.Logging.AddConsole();
var configValue = configuration["MySettings:Key"];

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✅ ASP.NET MVC

7. Explain MVC architecture with a real-time example.
MVC separates app into:

• Model: Business logic (e.g., Employee.cs)

• View: UI (e.g., Employee.cshtml)

• Controller: Connects model and view (e.g., EmployeeController.cs)

📌 Example: In an Employee Management System, /Employee/Index fetches data from DB and renders it via the View.

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8. Difference between TempData, ViewData, and ViewBag

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9. Types of Filters in MVC

• Authorization Filter

• Action Filter

• Result Filter

• Exception Filter

[Authorize]
[HandleError]

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10. How does routing work? Explain attribute routing.
Routing uses {controller}/{action}/{id?} pattern or attribute-based routing.

[Route("products/{id}")]
public IActionResult Details(int id) { ... }

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✅ SQL Server

11. SQL query to find second highest salary

SELECT MAX(Salary)
FROM Employees
WHERE Salary < (SELECT MAX(Salary) FROM Employees);

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12. Difference: Clustered vs Non-Clustered Index

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13. What is CTE (Common Table Expression)?
A temporary named result set used for modular queries or recursion.

WITH EmployeeCTE AS (
  SELECT Name, Salary FROM Employees WHERE Department = 'IT'
)
SELECT * FROM EmployeeCTE WHERE Salary > 50000;

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14. How to delete duplicate records but keep one

WITH CTE AS (
  SELECT *, ROW_NUMBER() OVER(PARTITION BY Name, Email ORDER BY Id) AS rn
  FROM Users
)
DELETE FROM CTE WHERE rn > 1;

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15. Difference: DELETE vs TRUNCATE vs DROP

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✅ Angular

16. Difference between Observable and Promise

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17. Template-driven vs Reactive Forms

• Template-driven: Simpler, uses ngModel, ideal for small forms

• Reactive: Uses FormControl, powerful for dynamic & complex forms

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18. What is an HTTP Interceptor?
Used to intercept HTTP requests and modify them (e.g., add headers).

intercept(req: HttpRequest<any>, next: HttpHandler) {
  const authReq = req.clone({
    headers: req.headers.set('Authorization', 'Bearer token')
  });
  return next.handle(authReq);
}

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19. What is Change Detection?
It checks for changes in component data and updates the DOM. Angular uses zone.js to detect async events like clicks or HTTP calls.

• Use ChangeDetectionStrategy.OnPush for performance boost.

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20. How to call and bind REST API data in Angular

this.http.get<Employee[]>('api/employees').subscribe(data => {
  this.employees = data;
});

Bind to HTML:

<div *ngFor="let emp of employees">{{ emp.name }}</div>

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These 20 questions will help you crack interviews, strengthen your understanding, and prepare solid content for blogging or technical discussions. If you're a full-stack developer working with .NET, Angular, and SQL—this is your 2025-ready cheat sheet!

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✍ Written by Rishabh Mishra