C# Dependency Injection – Interview Questions & Answers

Last updated: February 2026

What is Dependency Injection?

Dependency Injection (DI) is a design pattern where dependencies are passed rather than created internally.

Example

public class OrderService
{
    private readonly IEmailService _emailService;
    public OrderService(IEmailService emailService)
    {
        _emailService = emailService;
    }
}

Conclusion

DI is essential for .NET developers and commonly asked in interviews.