C# interview questions and online tests

The expert team at DevSkiller prepares C# interview questions and online tests aimed at hiring junior, middle, and senior-level C# developers.

DevSkiller C# interview questions and online tests are powered by RealLifeTesting™. The RealLifeTesting™ methodology is unique in that it tests candidates’ skills through real-world challenges rather than algorithmic problems. Recruiting your next C# developer can become a whole lot easier with DevSkiller C# interview questions and online tests.

Technologies covered:

Programming language: C#

C# frameworks and libraries: .NET, ASP.NET, MVC, Entity Framework, WCF, LINQ and others

Build tools: MSBuild

.NET
MIDDLE
Tested skills
Duration
70 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Medium

.NET | C# | Population Statistical Data Analyzer - The candidate must finish the implementation of 4 methods: two which parse data stored as JSON and prepare correct tree structure; the other two which search tree and return proper information by criteria.

.NET
JUNIOR
Tested skills
Duration
73 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, .NET Core, Basic Common topics, C#, Logging, Parallel Programming, Visual Basic .NET

Programming task - Level: Easy

.NET | .NET Core, Microservices | Traffic volume report api - Complete the implementation of a reports' microservice that should subscribe data registered by specialized microservices. The data must be saved in the local database. In the future the data will be used to generate reports for clients.

.NET
SENIOR
Tested skills
Duration
106 minutes max.
Evaluation
Automatic
Test overview

Code gaps

assessing knowledge of ASP.NET, C#, Security basics, .NET Core, Basic Common topics, Entity Framework Core, Logging

Programming task - Level: Hard

.NET | .NET Core | Company Web Page - Complete the implementation of a web page.

The page can be displayed in English or Spanish depending on the user's culture.

A user should have knowledge about the localized data annotation, the localized resources ant the action filters.

C#
MIDDLE
Tested skills
Duration
160 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Medium

.NET | MT101 Swift message parser and validator - Implement a parser and a validator for data that contains Swift MT101 messages.

C#
JUNIOR
Tested skills
Duration
64 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, Basic Common topics, Visual Basic .NET

Code gaps

assessing knowledge of .NET, Basic Common topics, C#, Visual Basic

Programming task - Level: Easy

.NET | Visual Basic | Sanction List Service - Complete the implementation of a service that scans and looks for transactions that contain words from asanction list. This task verifies the basic knowledge of VB.NET such as interfaces, classes, exceptions.

.NET
MIDDLE
Tested skills
Duration
156 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, Advanced memory management .NET, C#, Fundamentals of memory, Heap and stack, Memory allocation, .NET Core, Basic Common topics, Logging

Programming task - Level: Medium

.NET | .NET Core | MT101 Swift message parser and validator - Implement a parser and a validator for data that contains Swift MT101 messages.

.NET
SENIOR
Tested skills
Duration
180 minutes max.
Evaluation
Automatic
Test overview

Programming task - Level: Hard

.NET | Tools for custom map with POI - Implement the tools for POIs search (on the map) and calculate an optimal tour route from user's favorite points. Additionaly, finish the implementation of a self-hosted WCF service which should provide this functionality.

.NET
JUNIOR
Tested skills
Duration
80 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#, EntityFramework, ASP.NET, ASP.NET MVC, MVC

Programming task - Level: Easy

.Net | ASP.Net | Bookstore Inventory - Implement a couple of methods to manage bookstore inventory.

C#
SENIOR
Tested skills
Duration
75 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Hard

.NET | C# | Threads | Bank gateway for booking transactions in Central Accounting System - Implement the IBookingGateway interface (create own class in a separate file in theBookingGatewayService project and implement it) and finish implementation of the BookingGatewayFactory class, which should create objects of IBookingGateway.

.NET
MIDDLE
Tested skills
Duration
50 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#, EntityFramework

Programming task - Level: Medium

.Net | Entity Framework | Bank Application Client DB Module - The test verifies EF skills such as: save new data, manage object tracking and lazy loading.

.NET
MIDDLE
Tested skills
Duration
115 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Medium

.Net | .Net Core | Movie Repository - Implement missing repository methods for movies asp.net app. Task requires knowledge of sqlserver query language and usage of direct connection to database without ORM.

C#
SENIOR
Tested skills
Duration
309 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Hard

.Net | .Net Core | Back end Alone - Implement .NET Core MVC Model Binder and a simple graph algorithm to support request with a fancy format. This task consists of two objectives. First is to implement model binder that will properly parse incoming request into objective structure. Second objective is to sort this structure (graph) before further processing.

.NET
JUNIOR
Tested skills
Duration
50 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Easy

.NET | C# | Bank interface for Internet Banking System - Implement a CreateTransfer method which sould check and save the proper data, and a SearchTransfer method which should filter and return the proper information.

ASP.NET
MIDDLE
Tested skills
Duration
72 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#, EntityFramework, Entity Framework 6, ASP.NET, ASP.NET MVC, MVC

Programming task - Level: Medium

.NET | Reservations App | Implement validation rules - Implement validation rules used while adding a new reservation.

.Net
MIDDLE
Tested skills
Duration
115 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#, ASP.NET, ASP.NET MVC, MVC

Programming task - Level: Medium

.Net | SQLite | Movie Repository - Implement missing repository methods for movies ASP.NET app. Task requires knowledge of sqlserver query language and usage of direct connection to database without ORM.

.Net
JUNIOR
Tested skills
Duration
35 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#, ASP.NET, ASP.NET MVC, MVC

Programming task - Level: Easy

.Net | ASP.Net MVC | Comments Challenge - Implement an Index action for posts controller so that posts can be rendered appropriately into the Posts/Index view.

ASP.NET
MIDDLE
Tested skills
Duration
120 minutes max.
Evaluation
Manual
Test overview

Choice questions

assessing knowledge of .NET, C#

Code review task - Level: Medium

.NET - CollectionWrapper code review

Programming task - Level: Medium

.NET | Reservations App | Implement query methods - Implement two methods in ReservationsService - GetByDay and GetHallsFreeHoursByDay.

ASP.NET
MIDDLE
Tested skills
Duration
95 minutes max.
Evaluation
Automatic
Test overview

Choice questions

assessing knowledge of .NET, C#

Programming task - Level: Medium

.NET | Reservations App | Implement query methods - Implement two methods in ReservationsService - GetByDay and GetHallsFreeHoursByDay.

Recommended roles for our C# interview questions and online tests

  • C# Developer
  • Web Developer
  • Junior C# Developer
  • Senior C# Developer
  • C# Programmer
  • .NET Developer Back-End Developer
  • C# .NET Developer
  • C# Web Developer
  • Full Stack .NET Developer
  • .NET Software Developer
  • .NET Programmer
  • ASP.NET Developer

How our C# interview questions work

DevSkiller C# interview questions and online tests implement the RealLifeTesting™ methodology to challenge candidates to answer questions and solve problems, similar to those they have to deal with in the real world. The old days of developers reciting coding patterns were not efficient enough at deciphering who were the most qualified developers, RealLifeTesting™is the solution.

Within the initial screening stages of recruitment, recruiters can distinguish the exact strengths of a candidate. They can assess coding skills, critical thinking and how candidates handle time-management.

DevSkiller C# interview questions and online tests can provide your business with objective insight into exactly how well each of developer candidates will perform in the role.

Key features

  • Gain in-depth insight into candidates’ coding ability
  • Online tests accessible from anywhere in the world
  • Implementing RealLifeTesting™ offering candidates a greater user experience: use of their own IDE and clone to GIT, run unit tests, and access Stack Overflow/Github/Google for research.
  • Robust tools to prevent plagiarism and ensure test accuracy
  • Observe candidates’ undertaking of tests in real time
  • Save time with non-technical automated results
  • A C# coding test can assess any level of experience

Skills covered in our C# interview questions and online tests

  • C#
  • .NET
  • JSON
  • NUnit
  • QA
  • Selenium
  • Testing
  • .NET 5
  • .NET Core
  • Basic Common topics
  • Entity Framework
  • Logging
  • Microservices
  • Parallel Programming
  • RESTful Web Service
  • Visual Basic .NET
  • Action filters
  • Entity Framework Core
  • HTTP Headers
  • Localized data annotation
  • Localized resources
  • Logging
  • Security basics
  • User Culture
  • Web Page configuration
  • Interfaces
  • Regular Expressions
  • RESTful API
  • Visual Basic
  • Advanced memory management
  • Fundamentals of memory
  • Heap and stack
  • Interfaces
  • BST trees
  • WCF
  • Classes
  • Threads

What to look for in a C# developer

Developed by Microsoft in 2000 to combine the computing ability of C++ with the simplicity of Visual Basic, C# is a programming language based on C++ and similar to Java. Found in almost all Microsoft products, it is used mainly for developing desktop applications. When recruiting for a C# developer there are several important factors to address.

Your C# developer candidate will need to possess knowledge of C# unit testing frameworks like; nUnit, SpecFlow, MSTest and xUnit. Your candidate should also know how to use C# building tools such as TFS, TeamCity, Jenkins, Cruise Control .NET and Azure DevOps (old TFS).

DevSkiller’s C# interview questions and online tests are the perfect asset to your business’s recruitment strategy. Our screening tool tests candidates online, and automatically generated reports present the results in a simple and easy to follow way. Which means you don’t have to be an expert in C#, to be able to hire the perfect candidate for the role.

Build your own custom C# interview questions and online tests

Perhaps you want to take our C# interview questions and online tests to the next level and customize them to get more out of them? No problem.

The DevSkiller task wizard lets you build custom tests using your own codebase. You can select languages other than C# if required and choose the exact skills and technologies you want to test. With our customized C# interview questions and online tests you set the difficulty-level and duration of each test, all while being able to observe candidates in real-time. Finding your next C# developer has never been simpler.

Like the look of our C# interview questions and online tests but need proof?

If you’re still not 100% convinced by our screening tool, don’t worry. It’s sensible to want some assurances before you part with your company’s finances. Check out the following case study from one of our past clients and see what we did for them:

DB1

DB1 is a software development company. They develop robust and reliable solutions for medium and large companies.

When it came to DB1’s recruitment process, the company had 5 stages, one of them being a technical challenge. Candidates had 5 days to complete the challenge and the company needed the assistance of a developer to assess the results. Often the candidates would become disengaged with the challenges or need reminding to complete the tests on time. Thanks to the implementation of DevSkiller testing, DB1 saw instant improvement in their recruitment process.

With DevSkiller the entire technical test stage of recruitment for DB1 decreased, from around 5 – 10 days, to between 3 – 7 days with DevSkiller. Also, not only did the customer experience improve, but because our system offers automatically generated test results, there is now no need for an additional developer to be brought in for the assessment of tests.

DB1 quickened up their whole technical screening process. They are also much more confident that the candidates they select to proceed, are the right ones for the role.

 “DevSkiller reduced the time on the technical test stage and reduced our dependence on other areas. It was faster to approve candidates for the next stage since we had an automatic score. Now the revision process is faster, most of the time we have instant results and scores that help us decide which candidate is approved to the next stage of the selection process. Our candidates say it’s a great platform and it really tests their knowledge.”

Nathalia G.R. Da Silva– Employer Branding & Tech Recruiter at DB1 Group

Frequently asked questions

How long does it take to set up DevSkiller?

DevSkiller is designed to quicken up your recruitment process, so it is quick and simple to set-up. Really all that is required is for you to create your account with us. Once registered, there are hundreds of predefined C# tests at your disposal.

Testing is carried out online so all you need to do is send out a test invite and your candidates can get started working on their C# interview questions and online tests. We offer a wide selection of junior, middle, and senior-level C# online tests and you can limit how long each test will last.

What do candidates think of DevSkiller tests?

We receive regular feedback that candidates enjoy working on DevSkiller’s variety of online tests. For most, having a chance to finally prove their skills in a fair setting is refreshing and they appreciate that opportunity. Many developers often get asked to recite coding patterns and algorithms. Outdated challenges that don’t accurately reflect the work they do. By implementing RealLifeTesting into our C# interview questions and online tests, DevSkiller can get much closer to the real thing.

Candidates love that at DevSkiller we use conventions that are normal to developers, like unit testing, and cloning to GIT from a personal IDE. Once they are given a DevSkiller test, candidates appreciate that our approach is different to what they might have encountered before and that they are finally being given the chance to prove their skills in a fair setting.

What do you do about plagiarism?

You need to be able to trust the results of our tests so we do everything in our power to eliminate the chance of any plagiarism. A number of anti-plagiarism tools are implemented including checking the candidate’s entered code and looking at the way each question is answered. The answers are automatically cross-referenced with every answer received in our system, if there is a match we can categorically confirm that the candidate cheated and they can be eliminated from the assessment.

We can also use screen recording to check if the candidate is looking at a different screen when undertaking a test. As well as to implement a range of social listening tools, check the candidate’s IP address and use live pair notifications. This combination of tools means plagiarism will not go undetected.

DevSkiller logo TalentBoost logo TalentScore logo