Interview Questions for .NET Developers

Microsoft .NET Logo.NET developers work in all types of organizations doing all sorts of business, so they have to be prepared to answer a broad range of questions, some general, some narrowly focused.

Web applications often contain three or more tiers, such as technologies sent to the client, maintaining server-side frameworks, or the ability to jump between the server-side, Web server and database frameworks. Developers may specialize in one or more of these, or have a multidisciplinary skill set. So while the term “.NET developer” is broad, it’s also fairly abstract. Be prepared, then: If you’re on the hunt for a new position you’ll probably be asked general questions so managers can assess your level of expertise.

The following are commonly asked interview questions.

Gauging how current a .NET developer is can be summed up fairly quickly. Mike Giglio, recruiting manager at Randstad Technologies, begins with these simple questions.

Which .NET framework are you currently working on?

The interviewer wants to assess how up to date you are. There are frameworks that range anywhere from 1.1, 2.0, 3.5, and 4.0. Obviously, if you’re working on a 4.0, you’re working on the most current framework.

Are you familiar with, and have you worked with, the latest technologies, like WCF, WPF or Silverlight?

The answer to this question will vary depending on individual experience, but whatever your response (yes or no), follow-up with an explanation of what you do know about those technologies.

Which languages have you worked with in .NET technologies?

C#, VB.NET or C++

According to Chris Cosentino, Response Manager at Kforce’s National Recruiting Center, interviews for mid-level developers usually start by sussing out the candidate’s general exposure to the framework as a whole and its overall architecture and life cycle, as well as languages they work with to support .NET and their platform.

How many languages does .NET support right now and how is it able to support multiple languages?

The interviewer would want to hear how Microsoft is compiled and how programming languages differ, as well as your knowledge of different applications and platforms that support them. The answers pertain to what kind of .NET developer they’re seeking and their skill sets.

Since front- and back-end developers usually are asked different questions, Consentino threw the next two into the mix.

Front end question: What’s your general focus — WinForms or Web services? Is Javascript an object oriented language?

“I’d want to know how the candidate would utilize it,” he says. The answer would have to be more than a “yes,” and should demonstrate your knowledge about prototyping with Javascript

Back end question: “I’d start with the kind of database server. Is it Oracle based? If we’re looking for a SQL server, and the candidate is doing SQL programming, how does it pertain to the .NET platform?”

If you’ve been writing your own code with SQL VS code, you’d show an in-depth knowledge, which is what Consentino wants. “If they’re only using Microsoft programs that come with the tool set, then they haven’t done much of their own writing and specifically not doing their own core coding.”

Ruth Mora, Business Development Manager at Modis, works with high level candidates and offered several scenarios for interviews. Here are a few that stood out.

How would you identify under-performing or poorly performing loops?

For this one, you’ll need to understand performance monitoring — for example, code performance and memory leaks — and be able to discuss reviewing performance data in real time and from log files.

What are some common issues you’ve faced in multi-threading environments?

In this case, the interviewer wants to know if you can detect and debug a problem as well as write thread statement code. You may also want to discuss any special logging frameworks or debugging techniques that you’ve utilized.

Mora says that candidates should be able to nimbly discuss inheritance and polymorphism and how to use them most effectively. A sample question might be:

How does Java implement polymorphism?

The interviewer wants to hear how class inheritance, as well as method overloading and overriding, are used in Java and how these affect objects.

9 Responses to “Interview Questions for .NET Developers”

  1. Cide Jammer

    These questions are stupid! They should be asking questions like “What is an ORM”, “What is IOC/DI”, “How does MVC work”, “What namespace is used to read configuration from an app.config or web.config”.

    My god, no wonder all the jobs are outsourced to India.

  2. Amber Shinault

    Some of these questions may leave the recruiter and the candidate confused. A Web Form and a Web Service are not related at all. Why would you ask about Java polymorphism if you are talking to a .NET developer unless you would like a .NET/Java Developer? Why wouldn’t you ask them about .NET polymorphism? They just do not seem like general questions and I hope the interviewee does not ask the recruiter for clarification on some of these.

    • The thing is, Amber these ARE the questions recruiters are asking, whether they’re good ones or not. That’s really the point of the article — to let you know what to prepare for, even if you don’t like what you’re going to be asked.

      • Amber Shinault

        I’m not Var, but I think the writer should have asked Software Development Managers to provide questions and answers. I do not think that these recruiters understood the questions they are asking. What good are the questions if you do not understand the question? Also, some of the questions would not make sense to a developer. I suggest that the writer ask a developer or a development manager to review these questions.

  3. Elisabeth Greenbaum Kasson

    Thanks Amber, your comments are duly noted and you’re right. We were attempting to be as general as possible with the questions and it wasn’t the best approach for .NET. Won’t happen again.

    • Amber Shinault

      Some of these questions are not general and some are not .NET related, i.e. Java polymorphism. They will have both the recruiter and the candidate confused. It’s difficult to get general questions for technical positions from recruiters for multiple reasons. If you do get them from a recruiter, you may want to have senior developers review the questions. I would even dare to say it might be a little haphazard to get interview question opinions from just one developer. The first few questions are general and are a good start. The awkward questions are related to the front-end (incorrect comparison), back end question (it’s not an open ended question and uses awkward phrasing), and the Java polymorphism is misplaced (why not ask about .NET polymorphism)? I’m saying this as a recruiter, writer, and an MCAD.