interview questions

Real questions, asked on interview:


  1. What is compostion over inheritance?
  2. What is difference between struct and class? Why we use one or another?
  3. Which design patterns you used?
  4. Inversion of control and dependency injection
  5. Why we use static class or static method?
  6. Difference between overloading and overriding
  7. Didderence between Abstract class and interface
  8. What is SOLID?
  9. What is Singleton?
  10. What is Factory design pattern?
  11. Differenve between Dependency Inversion and Dependency Injection?
  12. Why you need Singleton in your application?
  13. Did you use Strategy pattern?
  14. What is Encapsulation, Abstraction, Inheritance and Polymorphism?
  15. Which order called constructor in base and child class?
  16. What is Decorator design pattern?


  1. Entify framework: pro and cons
  2. Unit tests, how they change process of development?
  3. Add new functionality withour breaking existing
  4. Two pays of passing parameters to query using ADO.NET
  5. What is serverless and why we use it?
  6. What is ‘using’ in C#?
  7. What is disposible?
  8. Difference between dispose and desctructor
  9. Difference betwnn IEnumerable and IQuerable
  10. Difference between String and StringBuilder
  11. String, is it reference or value type?
  12. What is nullable and why to use them?
  13. How to use conteiner for DI?
  14. How we use Singleton in DI?
  15. Name of container in DI
  16. Why we use interfaces in DI?
  17. Difference betwwen ref and out parameters
  18. How to keep session in MVC Core?
  19. Waht is difference between .NET and .NET Core?
  20. What is difference between TempData and ViewData?
  21. How to calculate number of visitors in MVC?
  22. What’s new in .NET Core 3.x?
  23. How SignalR works?
  24. How to use ajax in MVC?
  25. Routing in MVC
  26. What is CLR?
  27. What is GAC?
  28. Can we use Unit Tests for private methods?
  29. What is difference between .NET Core and .NET Standard?
  30. Did you use TPL?
  31. Multiple inherinace in C#?
  32. When you prefer ADO.NET or ORM (EF)?
  33. What is delegate?
  34. What is difference between Func and Action delegate?
  35. What is difference between Predicate, Converter and Comparison delegate?
  36. What is anonymous types in c#?
  37. How to parce Json?
  38. How to prevent double submission in MVC?
  39. How to validate information in MVC?
  40. What rules you have to write clean code?
  41. How to use GPU in .NET?
  42. What is deadlock?
  43. How to prevent deadlock?
  44. Weite Fibonacci function
  45. Which data structure use for file system modeling?
  46. What do you like in C#?
  47. Difference between Managed and Unmanaged code in .NET
  48. Difference between Hashtable and Dictionary in C#
  49. What is reflection?
  50. how to check is string empty or null
  51. check if string contain some text
  52. What is inteface?
  53. What is diffence using async for for I/O and CPU bound operations?
  54. What is generic and why we use it?
  55. When this keyword used in c# in static method?


  1. InProcess And OutOfProcess difference
  2. Run Application Pool under specific identity
  3. Session in ASP.NET
  4. What is cookieless session in
  5. What is difference between HttpHandler and HttpModule?
  6. Did you use SSO?
  7. Exception handling in ASP.NET
  8. What is minifing and bundling files?
  9. What is the difference between Web farm and Web Garden?
  10. How to send HttpWebRequest with Client Certificates?
  11. How to secure you web application?
  12. How works ASP.NET Core Blazor JavaScript interop?
  13. How to preveny SQL injection in EF?
  14. How to integrate backend with frontend?
  15. How you use RabitMQ?
  16. Why .NET Core is cross platform?
  17. Difference .NET Core and .NET Framework
  18. What is responsice design?
  19. Did you use accessibility design?
  20. Which tools you can use for bindling?

Web Services, Web API, WCF

  1. Which verbs are used in Web API?
  2. Can we use HttpPost to get info?
  3. Can we use Get to rend request in body?
  4. How to log every request?
  5. How to do autentification in Web Api?
  6. How to catch exeptions in Web Api?
  7. What is Web API gateway?
  8. How to use autentifiacation in Web API?
  9. How to use MFA?
  10. How to use cache in Web API?
  11. How to clean up cache?
  12. Pading data in Web API.
  13. In which .NET version Web API started?
  14. How to get data from Web Api?
  15. Difference between WCF and Web API
  16. How to use WCF without reference it?
  17. Which tools you use for debugging http request?
  18. Why you need use ConfigureAwait?
  19. Using keys in Web Api?
  20. How to use versioning in Web API and why we need this?

DB and SQL

  1. How to debug and fix query or SP?
  2. difference between primary key and unique key
  3. difference between primary key and primary index
  4. difference between SP and view
  5. difference between SP and function
  6. difference between truncate and delete
  7. difference between inner join, left join and right join
  8. difference between union and union all, except and intersect
  9. difference between having and where
  10. difference between clastered and nonclastered
  11. How to do unit testing for SQL?
  12. Some difference between old versions of SQL server and new
  13. Types of temporary tables
  14. Can SP return json?
  15. Trnsaction isolation level
  16. What is better: use SP or queries in the code?
  17. Did you use triggers?
  18. What is default schema?
  19. What is CQRS and why to use it?
  20. How to increasy queries perfomance?
  21. How to protect private information?
  22. What is main difference between SQL and NoSQL?
  23. What is transaction isolation level?
  24. What is difference between partition key and index in MongoDB?
  25. How to use MongoDB in your application?
  26. Did you use cursor?
  27. Did you use triggers?
  28. How to optimize SP perfomance?
  29. What is difference between clastered and non-clastered index?
  30. What is a CTE in SQL Server?

JavaScript and Angular, React

  1. Which JS Framoworks you used?
  2. How inheritance work in JS?
  3. How to bind data to field in jQuery?
  4. What is selection in jQuery?
  5. Difference between directive and expression in Angular
  6. Types of directives in Angular
  7. What is difference between Angular and AngularJS?
  8. What is virtual DOM in React?
  9. How to write some text to TextArea using JavaScript?
  10. how to call web api from angular?
  11. What do you like in JavaScript?


  1. What is difference between span and div?
  2. Draw a circle using css


  1. What Azure services you have used?
  2. How to scale application?


  1. How to create mobile app having web application?


  1. How we can do CD?

Agile and development

  1. Agile roles
  2. Story ponts
  3. Refactoring Techniques
Written on November 30, 2019