Job preparationProgramming languages
Programming language interview questions
Almost every IT interview opens with language questions — which one you prefer, why, and how you choose. Here is what your answer needs to cover.
The first question after you sit down will almost certainly be about languages. "Which is your favourite?" It sounds easy, and it is where a lot of people slip.
Because they are not really asking what you like. They are watching how you make a technical decision. So do not stop at "I enjoy Python" — say which language for which job, and why. Those first five minutes are where you can separate yourself.
The questions
What factors do you consider when choosing a programming language?
What to coverThe kind of project and what it needs (Python/JavaScript/PHP for web, Swift/Kotlin/Flutter for mobile, Python for data science, C/C++ for systems work); the language's performance (C/C++ where performance is critical, Python/Java for general work); syntax and readability; the libraries and frameworks available; the size and activity of the community; scalability and where the language is heading; the skills your team already has; and the cost of development and maintenance.
What is your favourite programming language and why?
What to coverThe honest answer is the best one. Name a language you have actually worked in, and give two reasons: the kind of work it suits, and something you built with it yourself. Then add one weakness. That last part shows you have used the language rather than merely liking it.
Which programming language have you used the most, and how many years of experience do you have with it?
What to coverDo not inflate the number — the next question will find you out. Give the years, then immediately name a project: what you built, how big it was, what your part was. "Two years, and in that time I built an inventory system where I handled the back end" lands far harder than "three years".
What algorithm would you use to solve a particular problem?
What to coverThe board is not listening for the name of an algorithm; it is listening for your method. Say: first I work out what the input looks like and how large it gets, then I start with the straightforward solution, then I look at where the time or memory is actually going — and choose searching, sorting, hashing or dynamic programming from there. On small data the simple solution is the right one.
Tips for this round
- Name a language you have genuinely worked in — the next question will go deeper.
- Mention one weakness too. Nothing but praise tells a board you read about it rather than used it.
- When you talk about experience, give a project name, not just a number of years.