100 C# Interview Questions

Learn how to answer C# questions well

Enroll Now

100 C# Interview Questions

Start to Finish Title Image

Learn how to answer C# questions well

Enroll Now
Video Lessons Icon 122 Lessons
Hours of Course Icon 5:49 Hours
Certificate Icon Certificate
Video Lessons Icon 122 Lessons
Hours of Course Icon 5:49 Hours
Certificate Icon Certificate

100 C# Interview Questions

You gain confidence through practice. But how do you practice technical interviews? By going through 20 of them.

This course will ask you real-world C# interview questions, including questions on technologies around C#. Get practice interviewing while also learning the answers to some of the questions you may have around C#.

Enroll Now
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Your Path to Confident Interviews

Round 1

Your first set of four interviews.

Course Introduction

By Tim Corey 1 lessons 4 min Preview
Introduction
4:17 min

Forum

Collaborative Student Space

Interview One

By Tim Corey 6 lessons 14 min
The Questions
0:31 min
What is the difference between a value type and a reference type in C#?
3:07 min
What is middleware in the ASP.NET Core pipeline?
2:03 min
What is git and what are some of the benefits?
2:50 min
What is a design pattern?
3:51 min
How do you use git to start working on a repository?
1:37 min

Interview Two

By Tim Corey 6 lessons 17 min
The Questions
0:29 min
What is WinForms?
2:45 min
What is WPF, and how does it differ from WinForms?
4:09 min
Explain the difference between string and StringBuilder.
3:01 min
How do MVC and Razor Pages differ?
3:09 min
Explain the Factory pattern.
3:19 min

Interview Three

By Tim Corey 6 lessons 13.5 min
The Questions
0:31 min
What is XAML?
2:57 min
What is the purpose of namespaces in C#?
3:01 min
What does the var keyword do, and when can you use it?
2:36 min
How is dependency injection configured in ASP.NET Core?
2:09 min
What problem does the Observer pattern solve?
2:17 min

Interview Four

By Tim Corey 6 lessons 7 min
The Questions
0:34 min
Describe the steps in git from making a change to getting it into the repository.
1:24 min
What is the MVVM pattern?
1:46 min
How do you display a simple message box in WinForms?
0:47 min
How do you display a simple message box in WPF?
1:17 min
How does the using statement relate to resource management?
1:33 min
Your Path Image

Milestone

Now you have some experience interviewing

Milestone Icon
Your Path Image

Round 2

Your second set of four interviews.

Interview Five

By Tim Corey 6 lessons 10 min
The Questions
0:35 min
What file defines environment-specific settings (e.g., Development vs. Production)?
2:25 min
How does the Decorator pattern work?
1:31 min
Define a dependency property in WPF.
1:16 min
What is the difference between a Form and a Control in WinForms?
1:03 min
Describe the Singleton pattern and a scenario for its use.
3:37 min

Interview Six

By Tim Corey 6 lessons 14 min
The Questions
0:40 min
What are the default options for settings in an ASP.NET Core project?
4:28 min
Where would you store settings that were specific to your machine?
2:15 min
How do you access settings in .NET?
2:33 min
How do you add your own source for settings?
2:32 min
Explain changes needed to get app config and web config to work in .NET
1:38 min

Interview Seven

By Tim Corey 6 lessons 11 min
The Questions
0:37 min
What is an event handler, and how do you wire one up?
0:46 min
Compare the three dependency injection service lifetimes in .NET.
3:38 min
What are the various ASP.NET Core web project types?
1:47 min
Compare Abstract Factory vs. Factory Method.
1:52 min
Explain the difference between git merge and git rebase.
2:44 min

Interview Eight

By Tim Corey 6 lessons 18 min
The Questions
0:39 min
Explain microservices vs monoliths and which you prefer.
4:36 min
Explain Docking vs. Anchoring for layout in WinForms.
2:48 min
How do you implement CORS in an ASP.NET Core app?
3:01 min
Explain async/await and how it differs from using Task.Run.
4:04 min
Describe the Facade pattern.
2:51 min
Your Path Image

Milestone

Now you should be understanding the format

Milestone Icon
Your Path Image

Round 3

Your third set of four interviews.

Interview Nine

By Tim Corey 6 lessons 22 min
The Questions
0:42 min
Compare an abstract class and an interface. When would you choose one over the other?
4:53 min
What are generics in C#, and why are they useful?
3:44 min
What is Dependency Injection, and how does it relate to patterns?
4:49 min
What is the purpose of the .gitignore file and how do you use it?
4:12 min
What techniques help virtualize large collections in a ListView or DataGrid in WPF?
3:24 min

Interview Ten

By Tim Corey 6 lessons 18 min
The Questions
0:34 min
How do you implement an MDI application in WinForms?
1:31 min
Explain the difference between struct and class.
3:18 min
What are some things to consider about nullability?
5:42 min
What is boxing and unboxing?
3:17 min
Describe the different types of properties and their options.
3:45 min

Interview Eleven

By Tim Corey 6 lessons 18 min
The Questions
0:32 min
Describe the difference between interfaces and inheritance.
7:16 min
How do you create and switch to a new branch in git?
0:35 min
Describe how you would implement logging in .NET.
5:16 min
When would a method benefit from being async?
1:25 min
Describe what health checks are and how they work.
2:58 min

Interview Twelve

By Tim Corey 6 lessons 17 min
The Questions
0:35 min
What is the difference between overloading and overriding a method?
3:15 min
What is the difference between const and readonly?
2:11 min
Explain the difference between shallow copy and deep copy.
3:20 min
What is the difference between the stack and the heap?
2:57 min
How does garbage collection work in C#?
4:52 min
Your Path Image

Milestone

Now you should be getting comfortable with the flow

Milestone Icon
Your Path Image

Round 4

Your fourth set of four interviews.

Interview Thirteen

By Tim Corey 6 lessons 19 min
The Questions
0:32 min
What is the purpose of the finalize and dispose methods?
4:38 min
Explain covariance and contravariance in generics.
3:14 min
What are anonymous types in C#?
2:47 min
What are Func<>, Action<>, and Predicate<> used for?
3:15 min
Explain the async and await keywords.
4:56 min

Interview Fourteen

By Tim Corey 6 lessons 15 min
The Questions
0:35 min
How does exception handling work with async/await?
2:07 min
What is reflection in C#? How is it used?
2:39 min
What is dynamic and what is it used for?
2:15 min
What is the difference between a record and a class?
4:51 min
What is the difference between authentication and authorization?
2:36 min

Interview Fifteen

By Tim Corey 6 lessons 14 min
The Questions
0:41 min
Describe the IDisposable pattern and how you implement it correctly.
1:47 min
What's the difference between a Razor page and a Razor Component?
2:15 min
When would you use an API vs GRPC?
1:55 min
Compare Entity Framework Code First to Database First.
2:42 min
Explain the difference between public, private, protected, internal, and protected internal.
4:43 min

Interview Sixteen

By Tim Corey 6 lessons 16 min
The Questions
0:35 min
What is polymorphism and encapsulation?
4:42 min
What is LINQ and when would you use it?
3:34 min
What is your error-handling strategy in C#?
4:45 min
Describe resolving a merge conflict in git step by step.
2:51 min
Describe the various rendering options in Blazor.
3:55 min
Your Path Image

Milestone

You should now feel more confident about answering questions

Milestone Icon
Your Path Image

Round 5

Your fifth set of four interviews.

Tooling Interview

By Tim Corey 6 lessons 18 min
The Questions
0:31 min
What is Docker and when would you use it?
5:33 min
What is Bootstrap and what are its benefits?
2:53 min
Explain what NuGet is and how it works.
3:37 min
Explain YAML and JSON.
2:38 min
What is Aspire and how does it help developers?
2:48 min

Databases Interview

By Tim Corey 6 lessons 38 min
The Questions
0:45 min
What are some differences between SQL and NoSQL databases?
10:17 min
What are primary keys, clustered indexes, and non-clustered indexes in Microsoft SQL Server?
10:01 min
Tell me about three database types you have used and what their strengths are.
2:48 min
What are some safety factors to consider when connecting C# to a database?
6:13 min
What are some things to consider when planning for database disasters?
8:22 min

CI/CD Interview

By Tim Corey 6 lessons 18 min
The Questions
0:40 min
What does CI/CD mean?
3:18 min
What are the differences between Azure DevOps and GitHub for CI/CD?
3:38 min
How do you check code quality in your CI/CD process?
3:20 min
What tools or strategies can you use to protect applications secrets?
4:14 min
How can a developer replicate the production environment locally?
2:45 min

AI Interview

By Tim Corey 6 lessons 23 min
The Questions
0:39 min
What is RAG and MCP?
4:52 min
Explain how an LLM comes to a conclusion.
2:22 min
What security implications are there around using AI in software development?
6:01 min
Tell me how you use AI in software development.
3:48 min
What are the benefits and drawbacks of integrating an LLM into a software product?
5:54 min

Course Conclusion

By Tim Corey 1 lessons 2 min
Conclusion
2:21 min
Course Completed

Certificate Awarded

Your Path Image

You Are an Experienced Interviewee

You are now able to....

Laurel One

Be confident answering interview questions.

Laurel Two

Know the answer to 100 common questions.

Laurel Three

Understand what makes a good interview answer.

Your Path to Confident Interviews

Round 1

Your first set of four interviews.

Course Introduction

1 lessons 4 min Preview
Introduction
4:17 min

Forum

Collaborative Student Space

Interview One

6 lessons 14 min
The Questions
0:31 min
What is the difference between a value type and a reference type in C#?
3:07 min
What is middleware in the ASP.NET Core pipeline?
2:03 min
What is git and what are some of the benefits?
2:50 min
What is a design pattern?
3:51 min
How do you use git to start working on a repository?
1:37 min

Interview Two

6 lessons 17 min
The Questions
0:29 min
What is WinForms?
2:45 min
What is WPF, and how does it differ from WinForms?
4:09 min
Explain the difference between string and StringBuilder.
3:01 min
How do MVC and Razor Pages differ?
3:09 min
Explain the Factory pattern.
3:19 min

Interview Three

6 lessons 13.5 min
The Questions
0:31 min
What is XAML?
2:57 min
What is the purpose of namespaces in C#?
3:01 min
What does the var keyword do, and when can you use it?
2:36 min
How is dependency injection configured in ASP.NET Core?
2:09 min
What problem does the Observer pattern solve?
2:17 min

Interview Four

6 lessons 7 min
The Questions
0:34 min
Describe the steps in git from making a change to getting it into the repository.
1:24 min
What is the MVVM pattern?
1:46 min
How do you display a simple message box in WinForms?
0:47 min
How do you display a simple message box in WPF?
1:17 min
How does the using statement relate to resource management?
1:33 min
Your Path Image

Milestone

Now you have some experience interviewing

Your Path Image

Round 2

Your second set of four interviews.

Training Icon

Interview Five

6 lessons 10 min
The Questions
0:35 min
What file defines environment-specific settings (e.g., Development vs. Production)?
2:25 min
How does the Decorator pattern work?
1:31 min
Define a dependency property in WPF.
1:16 min
What is the difference between a Form and a Control in WinForms?
1:03 min
Describe the Singleton pattern and a scenario for its use.
3:37 min
Training Icon

Interview Six

6 lessons 14 min
The Questions
0:40 min
What are the default options for settings in an ASP.NET Core project?
4:28 min
Where would you store settings that were specific to your machine?
2:15 min
How do you access settings in .NET?
2:33 min
How do you add your own source for settings?
2:32 min
Explain changes needed to get app config and web config to work in .NET
1:38 min
Training Icon

Interview Seven

6 lessons 11 min
The Questions
0:37 min
What is an event handler, and how do you wire one up?
0:46 min
Compare the three dependency injection service lifetimes in .NET.
3:38 min
What are the various ASP.NET Core web project types?
1:47 min
Compare Abstract Factory vs. Factory Method.
1:52 min
Explain the difference between git merge and git rebase.
2:44 min
Training Icon

Interview Eight

6 lessons 18 min
The Questions
0:39 min
Explain microservices vs monoliths and which you prefer.
4:36 min
Explain Docking vs. Anchoring for layout in WinForms.
2:48 min
How do you implement CORS in an ASP.NET Core app?
3:01 min
Explain async/await and how it differs from using Task.Run.
4:04 min
Describe the Facade pattern.
2:51 min
Your Path Image

Milestone

Now you should be understanding the format

Your Path Image

Round 3

Your third set of four interviews.

Training Icon

Interview Nine

6 lessons 22 min
The Questions
0:42 min
Compare an abstract class and an interface. When would you choose one over the other?
4:53 min
What are generics in C#, and why are they useful?
3:44 min
What is Dependency Injection, and how does it relate to patterns?
4:49 min
What is the purpose of the .gitignore file and how do you use it?
4:12 min
What techniques help virtualize large collections in a ListView or DataGrid in WPF?
3:24 min
Training Icon

Interview Ten

6 lessons 18 min
The Questions
0:34 min
How do you implement an MDI application in WinForms?
1:31 min
Explain the difference between struct and class.
3:18 min
What are some things to consider about nullability?
5:42 min
What is boxing and unboxing?
3:17 min
Describe the different types of properties and their options.
3:45 min
Training Icon

Interview Eleven

6 lessons 18 min
The Questions
0:32 min
Describe the difference between interfaces and inheritance.
7:16 min
How do you create and switch to a new branch in git?
0:35 min
Describe how you would implement logging in .NET.
5:16 min
When would a method benefit from being async?
1:25 min
Describe what health checks are and how they work.
2:58 min
Training Icon

Interview Twelve

6 lessons 17 min
The Questions
0:35 min
What is the difference between overloading and overriding a method?
3:15 min
What is the difference between const and readonly?
2:11 min
Explain the difference between shallow copy and deep copy.
3:20 min
What is the difference between the stack and the heap?
2:57 min
How does garbage collection work in C#?
4:52 min
Your Path Image

Milestone

Now you should be getting comfortable with the flow

Your Path Image

Round 4

Your fourth set of four interviews.

Training Icon

Interview Thirteen

6 lessons 19 min
The Questions
0:32 min
What is the purpose of the finalize and dispose methods?
4:38 min
Explain covariance and contravariance in generics.
3:14 min
What are anonymous types in C#?
2:47 min
What are Func<>, Action<>, and Predicate<> used for?
3:15 min
Explain the async and await keywords.
4:56 min
Training Icon

Interview Fourteen

6 lessons 15 min
The Questions
0:35 min
How does exception handling work with async/await?
2:07 min
What is reflection in C#? How is it used?
2:39 min
What is dynamic and what is it used for?
2:15 min
What is the difference between a record and a class?
4:51 min
What is the difference between authentication and authorization?
2:36 min
Training Icon

Interview Fifteen

6 lessons 14 min
The Questions
0:41 min
Describe the IDisposable pattern and how you implement it correctly.
1:47 min
What's the difference between a Razor page and a Razor Component?
2:15 min
When would you use an API vs GRPC?
1:55 min
Compare Entity Framework Code First to Database First.
2:42 min
Explain the difference between public, private, protected, internal, and protected internal.
4:43 min
Training Icon

Interview Sixteen

6 lessons 16 min
The Questions
0:35 min
What is polymorphism and encapsulation?
4:42 min
What is LINQ and when would you use it?
3:34 min
What is your error-handling strategy in C#?
4:45 min
Describe resolving a merge conflict in git step by step.
2:51 min
Describe the various rendering options in Blazor.
3:55 min
Your Path Image

Milestone

You should now feel more confident about answering questions

Your Path Image

Round 5

Your fifth set of four interviews.

Training Icon

Tooling Interview

6 lessons 18 min
The Questions
0:31 min
What is Docker and when would you use it?
5:33 min
What is Bootstrap and what are its benefits?
2:53 min
Explain what NuGet is and how it works.
3:37 min
Explain YAML and JSON.
2:38 min
What is Aspire and how does it help developers?
2:48 min
Training Icon

Databases Interview

6 lessons 38 min
The Questions
0:45 min
What are some differences between SQL and NoSQL databases?
10:17 min
What are primary keys, clustered indexes, and non-clustered indexes in Microsoft SQL Server?
10:01 min
Tell me about three database types you have used and what their strengths are.
2:48 min
What are some safety factors to consider when connecting C# to a database?
6:13 min
What are some things to consider when planning for database disasters?
8:22 min
Training Icon

CI/CD Interview

6 lessons 18 min
The Questions
0:40 min
What does CI/CD mean?
3:18 min
What are the differences between Azure DevOps and GitHub for CI/CD?
3:38 min
How do you check code quality in your CI/CD process?
3:20 min
What tools or strategies can you use to protect applications secrets?
4:14 min
How can a developer replicate the production environment locally?
2:45 min
Training Icon

AI Interview

6 lessons 23 min
The Questions
0:39 min
What is RAG and MCP?
4:52 min
Explain how an LLM comes to a conclusion.
2:22 min
What security implications are there around using AI in software development?
6:01 min
Tell me how you use AI in software development.
3:48 min
What are the benefits and drawbacks of integrating an LLM into a software product?
5:54 min
Training Icon

Course Conclusion

1 lessons 2 min
Conclusion
2:21 min
Your Path Image
Certificate Icon

Certificate Awarded

Course Completed

Your Path Image

You Are an Experienced Interviewee

You are now able to....

Laurel One

Be confident answering interview questions.

Laurel Two

Know the answer to 100 common questions.

Laurel Three

Understand what makes a good interview answer.

Ready to start your path?

Enroll Now

Ready to start your path?

Enroll Now
Picture of Tim Corey talking

Hi, I'm Tim COREY

I learned software development the hard way, with lots of dead-ends, confusion, and knowledge gaps. I kept thinking, “It shouldn't be this hard!” Now I teach students how to think and code like professional developers. My goal is to make it easier for you to become a developer.

25+

Years Experience

400,000

Students

400+

Hours Content

8x

Microsoft MVP

Don't Just Take My Word for It

“With your knowledge and teaching style I just got my first job offer as a C# developer”
Corey
“Definitely worth the money you pay.”
Zafar
“I really appreciate the explanation of “Why”
Jamie
“Thank you so much”
Daniel
“I'd feel better having a colleague that learned from Tim's courses than a bootcamp”
KUMBALA80
“After completing the mastercourse I got two very nice competing engineering offers”
Ron
“Best I've come across”
Chris
“I have finally landed my first job as a software developer”
Daniel
“If I only found this a year ago I could've saved so much time.”
Alex

Hi, I'm Tim COREY

I learned software development the hard way, with lots of dead-ends, confusion, and knowledge gaps. I kept thinking, “It shouldn't be this hard!” Now I teach students how to think and code like professional developers. My goal is to make it easier for you to become a developer.

Picture of Tim Corey talking

25+

Years Experience

400,000

Students

400+

Hours Content

8x

Microsoft MVP

Don't Just Take My Word for It

“With your knowledge and teaching style I just got my first job offer as a C# developer”
Corey
“Definitely worth the money you pay.”
Zafar
“Thank you so much”
Daniel
“I'd feel better having a colleague that learned from Tim's courses than a bootcamp”
KUMBALA80
“After completing the mastercourse I got two very nice competing engineering offers”
Ron
“I really appreciate the explanation of “Why”
Jamie
“Best I've come across”
Chris
“If I only found this a year ago I could've saved so much time.”
Alex
Picture of Tim Corey talking

Hi, I'm Tim COREY

I learned software development the hard way, with lots of dead-ends, confusion, and knowledge gaps. I kept thinking, “It shouldn't be this hard!” Now I teach students how to think and code like professional developers. My goal is to make it easier for you to become a developer.

25+

Years Experience

400,000

Students

400+

Hours Content

8x

Microsoft MVP

Don't Just Take My Word for It

“With your knowledge and teaching style I just got my first job offer as a C# developer”
Corey
“Definitely worth the money you pay.”
Zafar
“After completing the mastercourse I got two very nice competing engineering offers”
Ron
“I have finally landed my first job as a software developer”
Daniel
“Best I've come across”
Chris

Purchase or Subscribe

Enroll in the course or get it as part of a DevPass Subscription

100 C# Interview Questions

$97.00

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Learn More About DevPass

Purchase or Subscribe

Enroll in the course or get it as part of a DevPass Subscription

100 C# Interview Questions

$97.00

One time payment

White Checkmark on Black Circular Background 5:49 Hours of HD Video
White Checkmark on Black Circular Background Certificate
White Checkmark on Black Circular Background Forum Access
White Checkmark on Black Circular Background Source Code
White Checkmark on Black Circular Background English Subtitles
White Checkmark on Black Circular Background Downloadable
White Checkmark on Black Circular Background Lifetime Access
This course is not available in the DevPass until 2025-09-25T00:00:00Z.
DevPass Monthly Title Image

$55.00/m

Recurring Monthly Payment

Black Checkmark on White Circular Background 30 Courses
Black Checkmark on White Circular Background Certificates
Black Checkmark on White Circular Background Forum Access
Black Checkmark on White Circular Background Source Code
Black Checkmark on White Circular Background English Subtitles
Black Checkmark on White Circular Background Streaming Only
Black Checkmark on White Circular Background Life of Subscription
Black Checkmark on White Circular Background 400+ Hours of Video
Black Checkmark on White Circular Background $3.3K Total Value
Black Checkmark on White Circular Background Future Courses Added Shortly After Launch
Learn More About DevPass
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