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Stefan Ionel
Stefan Ionel

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60 tips and questions for .net backend developer interview in 2021

Hey guys,
Below is a list of questions that any back-end .net developer should know in 2021 interviews.

  1. Benefits of microservices?
  2. How would you design microservice? (what would be your ideas on how to split the monolith?)
  3. How can microservices communicate? (orchestration vs. choreography)
  4. How to track problems? (distributed tracing, CorrelationID)
  5. Lifecycle of the request (middlewares, attributes, registered implementation in Startup) - ActionFilters (before, after, namespace level?)
  6. Authentication, authorization (tokens, deserialization, how to add)
  7. System designs / architecture (monolith design, microservices advantages/disadvantages, scaling vertically/horizontally)
  8. Distributed tracing, logging between microservices
  9. VMWare vs Docker (do I need an operating system?)
  10. API Communications (how the microservices should communicate?)
  11. .NET Core experience?
  12. Dependency injection (any 3rd party library?, transient vs scoped, why to use transient?)
  13. EF (default objects lifestyle?, how to convert to transient, how to initialize CS?, replace on-the-fly?, code-first migration), what happens when there is a context change, lazy-loading vs. eager-loading)
  14. Delegate?
  15. Func vs regular function? Reason to have delegates?
  16. SignalR? How it works? (how to differentiate between two tabs?)
  17. Securing WebAPI? (something token based?, accessToken vs. refreshToken (what I am sending to get each?), which one has larger expiration?, slidin experience?)
  18. HTTP status codes (+ POST vs PUT )
  19. Best practices when building API, what should you consider
  20. Security of microservices (authentication, authorization)
  21. Domain Driven Design
  22. JWT (refresh/access token)
  23. What is CORS?
  24. Redis (what is special about that? distributed cache?)
  25. Task/Thread
  26. DBs - Indexes (clustered/non-clustered, index vs unique index)
  27. Which ORM? (EF, Dapper, lazy/eager loading)
  28. Locks on the DB
  29. How to switch the context based on the requests? (middlewares)
  30. IDisposable
  31. IQueryable vs IEnumerable
  32. IList vs List (difference, where to use it?)
  33. Using keyword
  34. Explicit conversion
  35. Int16 vs Int32 vs Int64
  36. unsigned vs signed int
  37. Paging (how it works, DB level, LINQ)
  38. Lazy loading vs eager loading
  39. Microservices (structure, how it works)
  40. RESTful vs SOAP (verbs)
  41. Difference between horizontal and vertical scaling
  42. What is long polling?
  43. Microservices (synchronous IO pattern, orchestration vs. choreography)
  44. Message vs. Event
  45. API Gateway
  46. Out vs. Ref parameter
  47. InnerJoin vs OuterJoin
  48. GroupBy and Having SQL statements
  49. Clustered vs. Non-clustered index
  50. Auto reset events vs. manual reset events
  51. Semaphore vs mutex
  52. Preflight requests
  53. Index scan vs Index seek
  54. DB examples (selects, indexes, order by)
  55. AutoMapper
  56. Dapper
  57. Show that you are able to work with blurry requirements
  58. Show that you are proactive, you are asking additional questions
  59. Show you are able to do tradeoffs

This list of questions was created using the platform We are hiring top

Say in a comment what question should be added for .net developer interviews.

Top comments (1)

davidkroell profile image
David Kröll

What about software design/architecture and systems architecture in general?

There is much more out there to talk about, not only the holy grail of microservices. Too many developers do not care about software architecture since microservices are introduced.

Microservices in general are a big challenge for the whole team/organization which do not only add benefits but also downsides.

Other crucial topics my opinion are software quality, automation and testing.