Interview questions by topic

Interview questions & answers by topic

Real, commonly-asked interview questions with clear answers across 22 core topics — computer-science fundamentals, databases, system design, aptitude and the top programming languages. Revise here, then practise out loud in a free AI mock interview.

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Interview questions by topic

Interview questions — FAQs

What topics do these interview questions cover?

OnJob has interview questions and answers for 22 core topics — Data Structures & Algorithms (DSA), DBMS (Database Management), Operating Systems, Computer Networks, OOP (Object-Oriented Programming), System Design and more — covering computer-science fundamentals, databases, system design, aptitude and the most-used programming languages.

Are the answers reliable?

Yes. Every answer is written from established, public-domain computer-science and programming knowledge and kept concise and correct. They reflect what interviewers actually expect, not filler — and you can rehearse them out loud in OnJob's free AI mock interview.

Are these interview questions free?

Yes, all topic interview questions and answers are free to read, and OnJob's AI mock interview is free to start (₹0). Pro (₹99/month) adds unlimited interview-prep AI alongside recruiter tracking and unlimited applications.

How should I use topic questions versus role-based mock interviews?

Use topic pages (DSA, DBMS, SQL, system design and so on) to revise fundamentals, then run a role-based AI mock interview on OnJob to practise the full set of questions for your specific job under realistic conditions.

Free AI mock interview

From reading to rehearsing

Practise these questions out loud with OnJob's free AI mock interview, get instant feedback, then apply to AI-matched jobs in one click.