Senior Software Developer Interview Questions And Answers

Show you’ve done your homework and that you have researched the company. Express your sincere desire to work at said company – but keep it balanced and don’t be sycophantic or overly enthusiastic and saccharine.

Be frank, but don’t just make it all about the money and the benefits. Obviously, these are important elements, and any recruiter knows that those two are key components in your decision-making process. But talk about workplace culture, creative fulfillment, the satisfaction of solving real-world problems etc.

The first question tests the way the candidate thinks when working with difficult bugs. Every candidate has their own process, but they must use a debugging tool, understand how to sift through each line of code using that tool, and then understand what must be done to fix the bug without affecting other code within a project.

The second question helps gauge how often a developer needs to debug his or her own code. Developers that need to spend a vast amount of their development time debugging may be ones who need extra help improving the code that they write.

Be honest. If you don’t have much experience in that particular language, tell them so – it’s not like you can wing it if you make it through to the technical interview. But point out what languages you are familiar with and express that you’re more than capable of learning. Remember, the desire and ability to learn is a hugely positive attribute and skill in itself.

Here’s your chance to expand on the answer above. Make those transferrable skills shine and relate them back to the role you’re applying for. Leading a team on a survival weekend to build a raft and cross a river uses the same leadership skills as leading a team of engineers to build something exciting and useful out of code that solves a problem.

Answer this in a balanced way. Avoid “Nothing. I hate it. The place sucks” responses. Pick a couple of elements that your company does well. The way they foster a good work/life balance or a family-like culture. Perhaps you enjoy your work, being able to create something that solves problems/fulfills a need. If this is your first job, talk about what you enjoyed while learning or interning.

Data is increasingly important. And employers like to know that you have the necessary skills to analyze data that’s presented to you, draw conclusions, and make informed decisions based on your analysis. Tell the panel about a scenario where you received data, whether that’s from surveys, interviews, beta testing, or customer usage, and the decision you made based on that. Did you work to improve accessibility? UX? UI? And so on. Be clear, concise, and detailed.

Object-relational mapping (ORM) is a way to use software code so it can map to database tables. This technique turns tables into their own classes, so then developers can use those classes for LINQ queries. The candidate might mention Hibernate, which is one of the most common ORM frameworks.

This is an important question, because it identifies how the candidate deals with obstacles, delays, and any problems that come up during the project. Most software development projects have hurdles of some kind, so a developer that has troubles identifying an obstacle with their previous project may raise a potential red flag. If you decide to hire a software developer, you need to know how they are able to overcome problems to get the job done and within the deadline.

While there’s no definitive right or wrong, this question is designed to test your knowledge, how well you articulate your process, and whether you’re a victim of tunnel vision. Think about it: if you say “Design. Or how well the team member’s code fits into the existing architecture”, you’re ignoring other elements that may be of equal import to the end result. What about:
☛ Functionality
☛ Readability
☛ Maintainability
☛ Security
☛ Simplicity
☛ Regulatory requirements
☛ Resource optimization

Come up with something that aligns with the culture of the company you’re interviewing for. What do you need to succeed? A steady supply of coffee? A relaxed atmosphere? A quiet space to complete your work or catch your breath? A communal/collaborative workspace?

Companies like to see that you’re a balanced person. Give them a little list of the things you enjoy most outside of work. Avoid saying that you’re a power gamer who spends 10 hours coding at the office, rushes home, and spends another 8 hours glued to your desktop monitor decimating your virtual foes. Instead, give a sense of balance, include a few different hobbies that include individuality – like reading (pick a genre), craft and DIY type hobbies, and other solitary pursuits, as well as more social or team activities, like gaming, maybe you’re a member of a field hockey club, or you are part of a local hiking group. Show the interview panel diversity in your interests. What you do outside of work tells your employers a lot about your personality and your skills, and how well you’d fit into their team. Think individuality, teamwork/collaboration, creativity, and problem-solving. Whatever you do, don’t say “I don’t have any hobbies.”

This question allows the engineer to openly discuss their previous project without getting too technical. There are several advantages with this discussion. The first one is that you can identify if the candidate worked with a team and if he or she was able to work together to brainstorm solutions. It also helps you understand their management skills, time estimates, interactions with project managers, and their contribution to the overall project.

This will help you understand how the candidate organizes their code. There is no one "right" way to answer this question, but your team probably has a set standard and it helps to know if the developer organizes code in a way that is easily maintained and can be further documented.

Be concise. Don’t ramble on and bore the recruiter. Be direct and succinctly describe the most notable/relevant projects you’ve been involved with at your current gig. If it’s your first job, again, be honest and instead describe some of your portfolio projects.

This is a time for you to shine, to tell the panel of your coding prowess, and describe the project you are most proud of. It doesn’t have to be that time when you built Facebook single-handedly in a single afternoon. It can be something as simple as building an app using a new language or your work on a collaborative project that solved a real problem faced by thousands of everyday folks. Don’t just brag. Yes, be confident and proud of your achievement, but try to relate the “why” to other people. “This is the project I’m most proud of because it filled a genuine need.”

Unit testing and test driven development (TDD) are often regarded as best practices in software development and code maintenance. Unit testing is an extra set of code that tests various methods and procedures for logic errors and coding flaws. This helps eliminate many of the bugs that could be promoted to production.

Every developer should be familiar with unit testing, and it’s important to know how much a software developer prioritizes it in their workflow.

☛ How many of the three variables scope, time and cost can be fixed by the customer?
☛ Who should make estimates for the effort of a project? Who is allowed to set the deadline?
☛ Do you prefer minimization of the number of releases or minimization of the amount of work-in-progress?
☛ Which kind of diagrams do you use to track progress in a project?
☛ What is the difference between an iteration and an increment?
☛ Can you explain the practice of risk management? How should risks be managed?
☛ Do you prefer a work breakdown structure or a rolling wave planning?
☛ What do you need to be able to determine if a project is on time and within budget?
☛ Can you name some differences between DSDM, Prince2 and Scrum?
☛ How do you agree on scope and time with the customer, when the customer wants too much?

☛ Do you know what a regression test is? How do you verify that new changes have not broken existing features?
☛ How can you implement unit testing when there are dependencies between a business layer and a data layer?
☛ Which tools are essential to you for testing the quality of your code?
☛ What types of problems have you encountered most often in your products after deployment?
☛ Do you know what code coverage is? What types of code coverage are there?
☛ Do you know the difference between functional testing and exploratory testing? How would you test a web site?
☛ What is the difference between a test suite, a test case and a test plan? How would you organize testing?
☛ What kind of tests would you include for a smoke test of an ecommerce web site?
☛ What can you do reduce the chance that a customer finds things that he doesn’t like during acceptance testing?
☛ Can you tell me something that you have learned about testing and quality assurance in the last year?

☛ How do you make sure that your code can handle different kinds of error situations?
☛ Can you explain what Test-Driven Development is? Can you name some principles of Extreme Programming?
☛ What do you care about most when reviewing somebody else’s code?
☛ When do you use an abstract class and when do you use an interface?
☛ Apart from the IDE, which other favorite tools do you use that you think are essential to you?
☛ How do you make sure that your code is both safe and fast?
☛ When do you use polymorphism and when do you use delegates?
☛ When would you use a class with static members and when would you use a Singleton class?
☛ Can you name examples of anticipating changing requirements in your code?
☛ Can you describe the process you use for writing a piece of code, from requirements to delivery?

☛ Can you name a number of non-functional (or quality) requirements?
☛ What is your advice when a customer wants high performance, high usability and high security?
☛ Can you name a number of different techniques for specifying requirements? What works best in which case?
☛ What is requirements tracing? What is backward tracing vs. forward tracing?
☛ Which tools do you like to use for keeping track of requirements?
☛ How do you treat changing requirements? Are they good or bad? Why?
☛ How do you search and find requirements? What are possible sources?
☛ How do you prioritize requirements? Do you know different techniques?
☛ Can you name the responsibilities of the user, the customer and the developer in the requirements process?
☛ What do you do with requirements that are incomplete or incomprehensible?

☛ What is something substantive that you've done to improve as a developer in your career?
☛ Would you call yourself a craftsman (craftsperson) and what does that word mean to you?
☛ Implement a <basic data structure> using <some language> on <paper|whiteboard|notepad>.
☛ What is SOLID?
☛ Why is the Single Responsibility Principle important?
☛ What is Inversion of Control? How does that relate to dependency injection?
☛ How does a 3 tier application differ from a 2 tier one?
☛ Why are interfaces important?
☛ What is the Repository pattern? The Factory Pattern? Why are patterns important?
☛ What are some examples of anti-patterns?
☛ Who are the Gang of Four? Why should you care?
☛ How do the MVP, MVC, and MVVM patterns relate? When are they appropriate?
☛ Explain the concept of Separation of Concerns and it's pros and cons.
☛ Name three primary attributes of object-oriented design. Describe what they mean and why they're important.
☛ Describe a pattern that is NOT the Factory Pattern? How is it used and when?
☛ You have just been put in charge of a legacy code project with maintainability problems. What kind of things would you look to improve to get the project on a stable footing?
☛ Show me a portfolio of all the applications you worked on, and tell me how you contributed to design them.
☛ What are some alternate ways to store data other than a relational database? Why would you do that, and what are the trade-offs?
☛ Explain the concept of convention over configuration, and talk about an example of convention over configuration you have seen in the wild.
☛ Explain the differences between stateless and stateful systems, and impacts of state on parallelism.
☛ Discuss the differences between Mocks and Stubs/Fakes and where you might use them (answers aren't that important here, just the discussion that would ensue).
☛ Discuss the concept of YAGNI and explain something you did recently that adhered to this practice.
☛ Explain what is meant by a sandbox, why you would use one, and identify examples of sandboxes in the wild.
☛ Concurrency
☛ What's the difference between Locking and Lockless (Optimistic and Pessimistic) concurrency models?
☛ What kinds of problems can you hit with locking model? And a lockless model?
☛ What trade offs do you have for resource contention?
☛ How might a task-based model differ from a threaded model?
☛ What's the difference between asynchrony and concurrency?
☛ Are you still writing code? Do you love it?
☛ You've just been assigned to a project in a new technology how would you get started?
☛ How does the addition of Service Orientation change systems? When is it appropriate to use?
☛ What do you do to stay abreast of the latest technologies and tools?
☛ What is the difference between "set" logic, and "procedural" logic. When would you use each one and why?
☛ What Source Control systems have you worked with?
☛ What is Continuous Integration? Have you used it and why is it important?
☛ Describe a software development life cycle that you've managed.
☛ How do you react to people criticizing your code/documents?
☛ Whose blogs or podcasts do you follow? Do you blog or podcast?
☛ Tell me about some of your hobby projects that you've written in your off time.
☛ What is the last programming book you read?
☛ Describe, in as much detail as you think is relevant, as deeply as you can, what happens when I type "cnn.com" into a browser and press "Go".
☛ Describe the structure and contents of a design document, or a set of design documents, for a multi-tiered web application.
☛ What's so great about <cool web technology of the day>?
☛ How can you stop your DBA from making off with a list of your users’ passwords?
☛ What do you do when you get stuck with a problem you can't solve?
☛ If your database was under a lot of strain, what are the first few things you might consider to speed it up?
☛ What is SQL injection?
☛ What's the difference between unit test and integration test?
☛ Tell me about 3 times you failed.
☛ What is Refactoring ? Have you used it and it is important? Name three common refactorings.
☛ You have two computers, and you want to get data from one to the other. How could you do it?
☛ Left to your own devices, what would you create?
☛ Given Time, Cost, Client satisfaction and Best Practices, how will you prioritize them for a project you are working on? Explain why.
☛ What's the difference between a web server, web farm and web garden? How would your web application need to change for each?
☛ What value do daily builds, automated testing, and peer reviews add to a project? What disadvantages are there?
☛ What elements of OO design are most prone to abuse? How would you mitigate that?
☛ When do you know your code is ready for production?
☛ What's YAGNI? Is this list of questions an example?
☛ Describe to me some bad code you've read or inherited lately.

☛ How would you implement the structure of the London underground in a computer’s memory?
☛ How would you store the value of a color in a database, as efficiently as possible?
☛ What is the difference between a queue and a stack?
☛ What is the difference between storing data on the heap vs. on the stack?
☛ How would you store a vector in N dimensions in a datatable?
☛ What type of language do you prefer for writing complex data structures?
☛ What is the number 21 in binary format? And in hex?
☛ What is the last thing you learned about data structures from a book, magazine or web site?
☛ How would you store the results of a soccer/football competition (with teams and scores) in an XML document?
☛ Can you name some different text file formats for storing unicode characters?

☛ What are metaphors used for in functional design? Can you name some successful examples?
☛ How can you reduce the user’s perception of waiting when some functions take a lot of time?
☛ Which controls would you use when a user must select multiple items from a big list, in a minimal amount of space?
☛ Can you name different measures to guarantee correctness of data entry?
☛ Can you name different techniques for prototyping an application?
☛ Can you name examples of how an application can anticipate user behavior?
☛ Can you name different ways of designing access to a large and complex list of features?
☛ How would you design editing twenty fields for a list of 10 items? And editing 3 fields for a list of 1000 items?
☛ What is the problem of using different colors when highlighting pieces of a text?
☛ Can you name some limitations of a web environment vs. a Windows environment?

☛ What do low coupling and high cohesion mean? What does the principle of encapsulation mean?
☛ How do you manage conflicts in a web application when different people are editing the same data?
☛ Do you know about design patterns? Which design patterns have you used, and in what situations?
☛ Do you know what a stateless business layer is? Where do long-running transactions fit into that picture?
☛ What kinds of diagrams have you used in designing parts of an architecture, or a technical design?
☛ Can you name the different tiers and responsibilities in an N-tier architecture?
☛ Can you name different measures to guarantee correctness and robustness of data in an architecture?
☛ Can you name any differences between object-oriented design and component-based design?
☛ How would you model user authorization, user profiles and permissions in a database?
☛ How would you model the animal kingdom (with species and their behavior) as a class system?