Preparing for a C# interview holds many similarities with preparing for other coding interviews. You can expect a similar interview structure, types of questions, and problems presented to you, though a C# interview will focus on C# concepts, as expected.
One of the trickiest challenges to face when preparing for a C# interview is the sheer number of concepts within any programming language. While it’s helpful to look up potential interview questions to give yourself some practice, the number of possible subjects there are can be overwhelming.
As intimidating as this can be, you do have an advantage in knowing you won’t have to discuss every aspect of C#. With so many concepts, there’s a chance your interviewer won’t have a checklist of specific questions that you must answer.
We’ll discuss core areas you should be familiar with later, but the topics you get asked about will likely develop with the answers you give. Often one response to an interviewer’s question will bring up a related issue or display of your knowledge level, which may be the subject of the next question you receive.
The higher-level position you’re aiming for, the more specific and in-depth information you’ll be expected to have in your interview. Your amount of experience will also play into this.
What Do Coding Interviews Look Like?
Overall, coding Interviews have a different structure than initial interviews. You’ll still want to use proper interview etiquette, but you can expect a more diverse range of questions that you would in a general HR interview.
The average time for coding interviews falls between ten and fifteen minutes, and they can be conducted in person or on the phone. While the spread of questions is going to vary on the company and the style of the interviewer, you should prepare for three major topics:
Depending on the position and company, you can also expect some variance in the questions you’ll be asked. If the company has a broader focus, they’re likely to ask broader coding questions in general.
If the company has a specific focus, you can expect questions about the type of work they do. For example, if you’re interviewing for a position where the primary responsibility is making Android apps, you can expect to answer questions about coding apps for Android devices.
Fundamental coding questions are built to determine your knowledge and understanding of the coding language. Some will be simple, such as “What is C#?” or “Explain C#’s features.” Others can go more in-depth and will expect you to explain differences between different functions or define complicated settings.
You can also expect the questions to test your knowledge of algorithms and smaller problem-solving skills. These coding questions are there to show your comprehension of C# and its functions. These questions are ones that will vary based on your experience and the level of the position.
Personality questions are the closest to what you would see in a primary interview structure, but they still have their distinctions. These questions will most often be about your previous projects or work.
While coding questions aim at understanding your knowledge of C#, personality questions are there to surmise your experience and scale of previous work with the language.
Whiteboarding questions take the knowledge tests of coding items and then put them to practical use. For these, you’ll have a coding prompt or problem, and then you must show how you would code to fulfill the prompt or solve the problem.
The name whiteboarding comes from that you write out your code on a whiteboard. For phone interviews, you’ll likely use a document sharer or some other online method to show your work.
Whiteboarding questions are essential for showing that you don’t just know C#, but also the skill to realize your ideas.
Preparing for a C# Interview
Knowing what to expect from the interview is one matter, but adequately preparing for a C# interview takes a bit more than that. Know that you know what you’ll be dealing with, though, the steps you need to prepare yourself are clear.
Improve Your Coding Skills
It seems obvious, but there’s no getting around it: to have a strong showing at a C# interview, you’re going to need to have strong coding skills. Your familiarity with C# is critical in this. You can’t answer coding questions without understanding the code you’re working with, so keep striving to learn as much about C# as you can.
Build Your Experience
Beyond just improving your knowledge base, you need to build your experience as well. Working on personal projects puts your skills to good use. As a bonus, you get to see where gaps in your coding knowledge are to help with the coding and whiteboarding questions.
Personal projects aren’t the only option to build experience. Internships, open source projects, and volunteer work all are options for furthering your practice with C#. Depending on the kind of work you do, you can even get paid in the process.
Refine Whiteboarding Skills
Your problem-solving skills may be the lynchpin of your C# interview. As such, you should practice solving coding issues. It’s best to write these out on paper so that you’re used to resolving problems by hand to prepare for whiteboarding in your actual interview. You can run the code afterward to make sure your solution is correct.
You don’t need to come up with potential problems on your own. There are various resources available that have possible C# interview whiteboarding questions available, both online and in books. Use these to your advantage.
Practice Mock Interviews
Mock interviews are a standard technique in preparing for an interview, and the same holds true when you’re looking into a coding position. Practicing with friends or family can help you refine the skills to answer the question types, plus prepare you mentally for the environment of an interview.
Specific C# Interview Preparation
As we mentioned before, the depth and range of question topics will vary based on the level of the position. The correlation is simple: entry-level jobs will focus on fundamentals, while higher-level positions can reach into more detailed and obscure topics. It’s crucial to understand where the job you’re aiming for falls.
As a rule of thumb, you want to have as much knowledge covering as broad an area as possible. C# on its own provides many opportunities, but a lot of software companies are now hunting for candidates that can work in several different levels, not just on one specialty.
C# interviews of all levels are expected to know the basic foundations of C#, from entry-level to senior management positions. If you can’t answer questions in these categories, then you don’t have much chance of earning the job as a programmer. Therefore, it’s critical that you have an extensive working knowledge of these topics:
- Object-Oriented Programming (OOP)
- SQL Server
Object-Oriented Programming is one of the major building blocks to C# interviews. You can expect for many of your questions on OOP. Do not neglect this category when preparing, as it is vital to your success.
ADO.NET connects to SQL Server to fetch data. You’ll need to be prepared to answer questions about connection pooling, DataReader vs. dataset, and the components of ADO.NET
As the framework for building web applications in Microsoft technology, ASP.NET becomes another critical component. Be ready to field questions about authentication and authorization, page life cycle, server controls, and user controls.
Another framework for C# development, .NET questions are another staple. As there are several versions, be sure that you’re familiar with the significant features of each. For these questions, make sure you understand delegates vs. events, boxing/unboxing, application domain, and the different types of code, like CAS, CLR, CTS, IL, and others.
SQL Server comes from RDBMS, which is one of the cornerstones of software projects. Depending on the interview, these questions can become very tricky. UNION and UNION ALL, views and cursors, stored procedures, triggers, and the first through third levels of data nominalization are all areas you should learn.
Once you have three to four years of experience, interviewers will expect more out of you. This level adds three more critical sections to your knowledge base:
Don’t neglect these topics if you’re aiming for senior positions. WCF is a widely discussed topic and is an essential part of your portfolio for higher level positions. MVC is gaining importance and may become part of the essentials in the years to come so that it can be a great addition to your skillset at the entry level.
Not all positions require EF. However, depending on the role, the company may want this skill. Don’t take the chance of being uninformed if it’s a requirement for the job.
Any coding language is vast, and C# is no exception. An interviewer won’t automatically disqualify you if you don’t know every end and angle, but the more skills you have at the ready, the better position you’ll hold. Pay close attention to the job description for these topics:
- Business Intelligence
The value of these will vary based on the role. Don’t neglect any of these if the job description lists them.
Senior Level positions will require the most knowledge of all C# roles. Be sure to be familiar with the topics listed below, as well as UML, design patterns, and other high-level issues.
Beyond just coding questions, you can also be expected questions about your current role and project management skills for a senior level role. Be prepared. Through a combination of knowledge, preparation, and practice, you should be able to prepare for a C# interview at any level adequately.