C#

What tasks does a developer face when scaling a solution to other checkpoints: new features, bugs, or core improvements?

What should you do if the network connection disappears during a REST request?

[Name] talked about the last place of work: what system it was, what specific tasks he performed, what technologies and patterns were used?

Why is distributing data across shards via customerId % shardCount problematic when changing the number of shards, and what solution should be used?

Middle

Альфа-Банк

public bool BookTour(string userId, DateTime start, DateTime end, int hotelId, string roomType, string flightClass, int airCompanyId, int flightnumber) { try { //flightClass also not desired to parse enum var flightInfo = new FlightInfo(Enum.Parse<FlightClass>(flightClass), airCompanyId, flightnumber); var resultBookFlight = _airWaysService.Book(GetUser(userId), flightInfo); //roomType also not desired to parse enum var rentInfo = new RentInfo(start, end, hotelId, Enum.Parse<RoomType>(roomType)); //GetUserId in a separate variable var resultBookHotel = _hotelService.Book(GetUser(userId), rentInfo); //Exceptions will go to inner, not caught Task.WhenAll(resultBookFlight, resultBookHotel); //Why static reservationIdAir = resultBookFlight.Result; _reservationIdHotel = resultBookHotel.Result; } catch (BookFlightException) { _hotelService.CancelBook(_reservationIdAir); return false; } catch (BookHotelException) { _airWaysService.CancelBook(_reservationIdHotel); return false; } catch (Exception ex) { throw new ApplicationException(ex.Message); } finally { //fields are 100% uninitialized //Why do we try to save something after exception //GetUser already extracted unitOfWork.Execute(async () => { await _tourRepository.Save(_reservationIdAir, _reservationIdHotel, GetUser(userId)); }).RunSynchronously(); //Interlock.Increment() _countBooked++; } return true; }

Middle

OZON

What is SOLID?

Middle+

OZON

Explain the concept of generation in a memory management system and its role in garbage collection.

Tell about the difference between interfaces and abstract classes. Why was default implementation introduced in interfaces?

Kafka — have you worked with it, tell about its features?

Where do you see yourself in five years?

Middle+

OZON

This is a query execution plan select b, sum(d) from T group by b for table create table T (A int not null primary key, b int, c int, d float). The table has no foreign keys. How to reduce the query execution time?

What is asynchrony and how have you applied it in your work?

Middle+

Тензор

How were distributed transactions implemented in microservices? Did you use sagas?

What is the complexity of inserting into a List and Dictionary? What are collisions in dictionaries?

How to write text to a file simultaneously from two different tasks? How to synchronize access?

Are there tasks you dislike or want to do less?

RabbitMQ — have you worked with it, tell about its features?

In which direction do you want to grow professionally?

Middle+

Pyrus

How does List differ from IEnumerable?

What methods can improve the performance of LINQ queries?