Junior Software Developer Interview Questions UK: 8 Real Questions and What Interviewers Want

Most Junior Software Developer interviews in the UK follow a pattern, and knowing it beats guessing. Below are eight questions from our bank of 25, each with a note on what the interviewer is really after.

Eight Junior Software Developer interview questions, and what the interviewer is thinking

1. Tell me about the programming languages you know best and how you've used them.

Why they ask: They want to gauge your real working knowledge and how honestly you describe your level.

2. Why do you want to be a software developer, and why at this stage of your career do you want to join us?

Why they ask: They want to see genuine motivation and that you understand what a junior role offers and demands.

3. Can you explain what version control is and how you use Git day to day?

Why they ask: Every junior developer must be comfortable with Git, since it underpins teamwork.

4. What are the main principles of object-oriented programming?

Why they ask: This is a very common junior question testing foundations learned in your degree or training.

5. How would you go about debugging a problem in your code?

Why they ask: Debugging is a daily activity, and they want to see a methodical approach rather than trial and error.

6. What is the difference between a list, a dictionary and a set, and when would you use each?

Why they ask: Choosing the right data structure is basic but essential, and shows whether you think about efficiency.

7. You've been given your first ticket, but you don't understand what it is asking for. What do you do?

Why they ask: They want to see whether you ask good questions early rather than guess or stay silent.

8. Tell me about a time you got stuck on a technical problem and how you got yourself unstuck.

Why they ask: They want evidence of resilience, resourcefulness and appropriate help-seeking.

A sample answer to question 1

Tell me about the programming languages you know best and how you've used them.

My strongest language is C#, which I used for most of my degree and my placement year, building a small REST API with ASP.NET Core and Entity Framework against SQL Server. I'm comfortable with object-oriented design, LINQ, async and await, and writing unit tests with xUnit. I'd describe myself as confident with the fundamentals but still learning the finer points of performance and architecture. I've also used JavaScript and a little React for front-end work on a personal project, and Python for scripts and data tidying, though I'd rate myself as intermediate there rather than expert. I'm honest about that distinction because I'd rather say where I need support than overpromise. What I do know is how to pick up a new language quickly, since the underlying ideas, such as data structures, control flow and testing, carry across. If your stack is different from mine, I'd expect to be productive in a few weeks with some guidance.

Common mistake to avoid: Listing every language you have touched; Overstating your ability

Want the rest?

Full model answers, key points and common mistakes for all 25 questions are on the Junior Software Developer interview questions page. The first five are free, no sign-up needed.