Through custom software programming, companies are looking to ASP.NET application developers to gain a competitive advantage. The demand for such developers is high with many being able to choose from various offers. If you are looking for a job this is great news, however, it’s a headache if you are looking for an expert.
The questions and possible answers below will help you carry out successful ASP.NET interviews to narrow down your candidates. Each question can be adapted to fit the needs of your company and don’t forget to bring in one of your IT team members if you aren’t confident in the tech language.
Where to start?
Begin with the usual “get to know” your candidate questions and then move on to general questions of the framework, when the candidate responds, focus on who they go about solving problems.
12 Questions to ask in an ASP.NET Interview
What is ASP.NET and why would it be used?
Some of the interviewees will head straight to the development side of the framework and respond by talking about its deployment, how compatible it is with common databases or the multi-language support. You may have candidates who discuss outcomes, the powerful websites that can be developed, the scalability and the strength of the ASP.NET community.
This question, regardless of the answer, will allow you to see how a candidate views ASP.NET. more importantly, if you are non-technical, you will see how a candidate explains technical structures to those with less knowledge.
What is ASP.NET Core?
ASP.NET is from Microsoft. ASP.NET Core is an open-source version, which first came out in 2016. Most people should know that it runs on macOS, Linux, and Windows. See if your candidate explains that it has been rewritten to allow for changes like the single model integration of MVC and Web API.
Explain how .NET supports multiple languages
This question will permit certain candidates to stand out. Everybody knows that .NET supports multiple languages but when you ask how the question becomes more complex.
The ideal you will be looking for is that .NET languages have to comply with the Common Language Runtime standard. As code written in .NET is a Microsoft Intermediate Language, there are no limitations.
What is a Postback?
This is when an online user asks for a server response from the site they are on. Examples are more obvious than you may think, when you click on submit, for example, as the website will then send some kind of confirmation or response back to the client. Postbacks will cause the page to reload. On the other hand, a Callback will extract data without the need to reload the page.
At this point, you will want to get into more detail and you may want a tech expert to step in.
What happens when a try-catch block doesn’t find an exception?
This is a way to handle exceptions in C# and other languages. It’s similar to saying trial and error. Next comes the final block, executed whether the exception has occurred or not. If your candidate has worked in production environments, try-catch and finally will be nothing new to them
What are the pros and cons of user controls and custom controls?
This question is aimed at both knowledge and how they approach application design with ASP.NET. Pay attention to the candidate’s answers regarding what they have learned rather than an answer memorized from the Internet. Here are the significant differences between user controls and custom controls:
User controls can be created easily and are preferable for static layouts as there is not so much support when it comes to visual design tools.
Custom controls are better for dynamic layouts because of the greater number of design tools. They do take longer to build.
Can you explain some of the page events in the life cycle of an ASP.NET page?
This is an applied technical question for developers. The candidate should know about the complete life cycle. On top of this, they should be confident in implementation and the maintenance of code and controls throughout each stage.
- Prelnit- after the start page is complete but prior to initialization. In this stage, developers are able to create dynamic controls and set the master page.
- InitComplete- occurring towards the end of the initialization stage. You can change the ViewState
- Control events- this happens in the Load stage. This is when certain control events are handled, for example, TextChanged event or Click event.
Have you worked with and IIS versions?
IIS (Internet Information Services) is an extensible web server. It supports a number of popular Microsoft transfer protocols. The present version is 10.0, supporting HTTP/2.
If a developer hasn’t worked with the latest versions this could be because their previous employer did not have it. You will be able to deter whether they have worked with 10.0 or at least know of its advantages.
How can you stop CSRF attacks?
This question is designed to test the interviewee’s experience with real-world applications and potential security risks. A Cross-Site Request Forgery is when a fake request is sent to a web application from a user’s browser.
When using ASP.NET, attacks can be prevented with the use of authentication codes. A request is issued a token, the token is returned along with the request and the validated server-side. If you require more information, ask how ASP.NET handles other potential security problems.
What is MVC in ASP.NET?
MVC allows for straightforward building and testing and it’s something that must be included in every interview. Each app can be broken into three parts:
- Model- The data domain of an app, often an actual SQL database. Records are retrieved and updated by model objects.
- View- Visual components that make up the user interface.
- Controller- What creates the user interaction, i.e. keyboard input.
You may decide to follow up with questions about the difference between the older forms of ASP.NET and the right answer will include the advantages of ASP.NET MVC, the individual testing, loading entire apps, and rapid testing.
How do you use multiple models in a single view?
Here, you are looking for how a candidate can get around one model being bound in each view. Possible solutions include class ExpandoObject, ViewModel class, ViewData, and/or ViewBag. Other candidates might mention JSON, Tuple, and RenderAction.
Remember, you aren’t just looking for a list of solutions. Your candidate should be able to explain how their solution functions.
Explain how stateful and stateless differ
HTTP is stateless. There is no built-in support for recording states and therefore doesn’t have the ability to store data relating to actions that are taken by a user. ASP.NET MVC is also stateless, as it doesn’t utilize server-side controls.
ASP.NET Web Forms attempted to make stateful apps with ViewState where the state was managed on a server.
Your interview questions should allow candidates to demonstrate not just their technical knowledge but also their awareness of ASP.NET. Include questions that allow you to learn about their past projects, their achievements, and where they can see themselves in the future. Your candidate will appreciate your interest in their future.