Senior .NET Developer interview questions and answers
This Senior .NET Developer interview profile brings together a snapshot of what to look for in candidates with a balanced sample of suitable interview questions. Consider modifying these .NET developer interview questions to suit your company’s specific needs and upcoming projects.
10 good senior .NET developer interview questions
- What does a Just in Time compiler have to offer?
- How is a preemptive threading model different from the cooperative threading model?
- What tools & practices would you consider necessary for a Continuous Delivery solution?
- How is a code point related to a code unit in Unicode?
- What do you think makes a unit test good? What about functional ones?
- Can you discuss basic algorithms and how you would find, think, or sort using them?
- Do you have an approach to modeling?
- Are you active on Github? Do you contribute to any open-source software projects?
- Who are you following on Twitter and which blogs do you turn to for staying updated?
- Do you have any side projects, like game development?
Here are 10 essential interview questions and sample answers to help identify the best candidates for this role.
1. What does a Just in Time compiler have to offer?
This question aims to assess the candidate’s understanding of Just in Time (JIT) compilation in the context of .NET.
Sample answer:
“The JIT compiler offers runtime compilation, converting intermediate code into native machine code just before execution. This allows for optimizations tailored to the runtime environment.”
2. How is a preemptive threading model different from the cooperative threading model?
This question evaluates the candidate’s knowledge of threading models, which is crucial for building scalable .NET applications.
Sample answer:
“In a preemptive threading model, the operating system controls thread execution. In a cooperative model, threads yield control voluntarily. Preemptive threading is generally more efficient but can lead to thread starvation.”
3. What tools & practices would you consider necessary for a Continuous Delivery solution?
This question gauges the candidate’s familiarity with DevOps practices, particularly Continuous Delivery, in a .NET environment.
Sample answer:
“For Continuous Delivery, I’d consider tools like Jenkins for automation, Git for version control, and Docker for containerization. Practices would include automated testing and configuration management.”
4. How is a code point related to a code unit in Unicode?
This question tests the candidate’s understanding of Unicode, which is important for internationalization in .NET applications.
Sample answer:
“A code point is a unique number that maps to a specific character in Unicode. A code unit is the storage unit used to represent that code point in memory.”
5. What do you think makes a unit test good? What about functional ones?
This question assesses the candidate’s approach to testing, a key aspect of software quality.
Sample answer:
“A good unit test should be isolated, repeatable, and quick to execute. Functional tests, on the other hand, should validate that the system works as expected from the user’s perspective.”
6. Can you discuss basic algorithms and how you would find, think, or sort using them?
This question aims to evaluate the candidate’s algorithmic thinking, crucial for problem-solving in software development.
Sample answer:
“For sorting, I often use quicksort or mergesort depending on the use-case. For searching, binary search is efficient when the data is sorted.”
7. Do you have an approach to modeling?
This question assesses the candidate’s approach to software design and architecture.
Sample answer:
“I usually start with identifying the key entities and their relationships. Then I use UML diagrams to visualize the architecture before diving into coding.”
8. Are you active on Github? Do you contribute to any open-source software projects?
This question gauges the candidate’s involvement in the broader software development community.
Sample answer:
“Yes, I am active on Github. I contribute to a few open-source projects related to data analytics and machine learning.”
9. Who are you following on Twitter and which blogs do you turn to for staying updated?
This question evaluates the candidate’s commitment to staying current in the field.
Sample answer:
“I follow industry leaders like Scott Hanselman and read blogs like Stack Overflow and MSDN to stay updated.”
10. Do you have any side projects, like game development?
This question assesses the candidate’s passion for software development beyond their day job.
Sample answer:
“Yes, I’m currently working on a mobile game using Unity and C#. It’s a great way to explore different aspects of software development.”
What does a good senior .NET developer candidate look like?
A strong candidate should have a deep understanding of .NET technologies, be proficient in algorithmic thinking, and show a commitment to continuous learning and community involvement.
Senior .NET Developer Interview Questions
In some respects even the most technical role demands qualities common to strong candidates for all positions: the willingness to learn; qualified skills; passion for the job.
Even college performance, while it helps you to assess formal education, doesn’t give a complete picture. This is not to underplay the importance of a solid background in computer science. These interview questions for a .NET developer can help you gauge their competency in computer science:
• Understanding of basic algorithmic concepts
• Discuss basic algorithms, how would they find/think/sort
• Can they show a wider understanding of databases
• Do they have an approach to modelling?
Consider these senior developer interview questions when determining their investment in the industry. Do they stay up to date with the latest developments? If so, how? Probe for their favorite technical books. Who are they following on Twitter, which blogs do they turn to?
Are they active on Github? Do they contribute to any open source software projects? Or take part in Hackathons. In short, how strong is their intellectual interest in their chosen field? How is this demonstrated? Ask for side projects (like game development). Committed, inquisitive candidates will stand out.
Let’s summarize some of the questions and add a few more divided into specific types.
Computer Science questions
- What does a Just in Time compiler has to offer? Do you know of any programming language runtimes that use one?
- How is a preemptive threading model different from the cooperative threading model?
- What tools & practices would you consider necessary for a Continuous Delivery solution?
- How is a code point related to a code unit in Unicode?
- What do you think makes a unit test good? What about functional ones?
Role-specific questions
- How does MSIL (intermediate language) fit into the whole .NET framework architecture?
- What do you mean by polymorphism, inheritance and encapsulation?
- What is the await keyword? Describe a use case and the needed code modifications in order to use it.
- How can lazy initialization be accomplished in .NET?
- Please explain the “virtual” keyword
- Why would you declare a field as volatile?
- What is the Entity Framework and what are the benefits of using it?
- What is Reflection in .NET? Please describe a use case and the benefits of using it.
- What is the dynamic type in .NET? Please describe a use case.
- What do we mean when we say that a certain Lambda expression forms a closure?
- How are anonymous classes instantiated in .NET? Can they be passed as function params?
- In LINQ, what is the difference between the IQueryable and IEnumerable interface?
- What are the benefits of using the Aggregate method in LINQ?
- Is it possible in .NET to extend a class (any class) with some extra methods? If yes, how can it be accomplished?
- In .NET, attributes are a method of associating declarative information with C# code. Please describe the way they are used and a proper use case.