This guide provides a comprehensive list of C# interview questions tailored for candidates with 7 years of experience. These questions go beyond the basics, testing your deep understanding of the language, its nuances, and best practices. Expect a mix of conceptual, practical, and problem-solving questions.
Core C# Concepts & Advanced Topics
This section focuses on your fundamental understanding of C# and its advanced features. A strong candidate should be able to articulate concepts clearly and provide practical examples.
1. Garbage Collection (GC):
- Explain the different generations of garbage collection in .NET. Discuss how this impacts performance and memory management.
- Describe scenarios where you'd need to influence the GC's behavior. (e.g., using
GC.Collect(), understanding finalizers). Discuss the trade-offs. - What are weak references and when would you use them? Explain their role in preventing memory leaks.
2. Multithreading and Concurrency:
- Explain the differences between
Task,Thread, andasync/await. When would you choose one over the others? - Describe common concurrency patterns (e.g., Producer-Consumer, Reader-Writer). Provide examples of how you've used them in your projects.
- How do you handle deadlocks and race conditions? Discuss techniques like locks, mutexes, semaphores, and monitor objects.
- Explain the concept of thread synchronization and the challenges involved. Discuss different synchronization primitives and their use cases.
3. LINQ (Language Integrated Query):
- Describe the benefits of using LINQ. How does it improve code readability and maintainability?
- Explain different LINQ operators (e.g.,
Where,Select,GroupBy,Join). Provide code examples demonstrating their usage. - How can you perform efficient queries with large datasets using LINQ? Discuss optimization strategies.
- Discuss the differences between LINQ to Objects, LINQ to SQL, and LINQ to Entities.
4. Design Patterns:
- Explain the SOLID principles. Provide examples of how you have applied them in your projects.
- Discuss various design patterns (e.g., Singleton, Factory, Observer, Dependency Injection). Provide examples of when you've used them and why they were appropriate choices.
- Describe your approach to designing scalable and maintainable applications. How do design patterns contribute to this goal?
5. .NET Framework vs .NET Core/.NET:
- Explain the key differences between the .NET Framework and .NET (Core/6+).
- Discuss the advantages of using .NET over the .NET Framework.
- Explain your experience working with different .NET versions.
Practical Application & Problem Solving
This section assesses your ability to apply your knowledge to real-world scenarios.
6. Error Handling and Exception Management:
- Explain your approach to handling exceptions. Discuss the use of
try-catch-finallyblocks and best practices for exception logging. - Describe different exception handling strategies (e.g., using custom exceptions, exception filtering).
- How do you ensure that exceptions don't bring down your application?
7. Working with Databases:
- Describe your experience with different database technologies (e.g., SQL Server, MySQL, PostgreSQL).
- Explain how you interact with databases from C# applications (e.g., using ADO.NET, Entity Framework Core).
- Discuss techniques for optimizing database queries and improving performance.
8. Code Optimization and Performance Tuning:
- Explain your approach to identifying performance bottlenecks in C# applications.
- Discuss techniques for optimizing C# code for performance (e.g., using appropriate data structures, minimizing allocations).
- How do you measure and analyze the performance of your code?
9. Testing and Debugging:
- Describe your experience with different testing methodologies (e.g., unit testing, integration testing). Mention specific frameworks used (e.g., xUnit, NUnit, MSTest).
- Explain your debugging techniques. How do you identify and resolve issues effectively?
10. Security Considerations:
- Discuss common security vulnerabilities in C# applications and how to mitigate them.
- Explain your experience with secure coding practices.
This extensive list provides a strong foundation for your C# interview preparation. Remember to tailor your answers to your specific experiences and highlight your achievements. Good luck!
