Software Engineer interview questions & mock practice
What interview questions are asked for a Software Engineer?
A Software Engineer interview in 2026 runs across 4 rounds — online assessment, dsa / problem solving, system design, hiring manager / culture fit. Below are the most-asked Software Engineer interview questions and a focused prep plan. Rehearse every answer out loud with the free timed practice below before the real one.
- Data Structures
- Algorithms
- System Design
- OOP
- SQL
- Git
- Problem Solving
Free interview practice · Software Engineer
Practise your Software Engineer interview now — free
Step through the 12 most-asked Software Engineer questions one at a time, under a timer, just like the real thing. Jot your answer, then reveal what a strong answer covers. No signup needed to practise.
The Software Engineer interview process
Coding, data structures, algorithms and system design — the core software engineering loop used by product companies and startups across India.
1. Online assessment
Timed coding problems on arrays, strings and hashing on HackerRank or HackerEarth.
2. DSA / problem solving
1–2 live coding rounds on data structures, algorithms and complexity analysis.
3. System design
Designing a scalable service (mid/senior); low-level design for early-career.
4. Hiring manager / culture fit
Past projects, ownership, behavioural questions and team fit.
Most-asked Software Engineer interview questions
12 of the questions Software Engineer candidates are asked most often in India. Practise answering each one out loud in the timed practice above.
- 1. Reverse a linked list, both iteratively and recursively.
- 2. Find the two numbers in an array that add up to a target sum.
- 3. Detect whether a linked list has a cycle.
- 4. What is the difference between a process and a thread?
- 5. Explain time and space complexity (Big O) with examples.
- 6. How does a hash map work internally, and what happens on collisions?
- 7. Find the longest substring without repeating characters.
- 8. What is the difference between an array and a linked list?
- 9. Explain the difference between SQL and NoSQL databases.
- 10. How would you design a URL shortener like bit.ly?
- 11. What happens when you type a URL into a browser and press enter?
- 12. Tell me about a challenging bug you fixed and how you approached it.
How to prepare for your Software Engineer interview
Drill 150–200 DSA problems on arrays, strings, hashing, trees and graphs — pattern recognition beats memorising solutions.
Always state your approach and complexity out loud before you start coding; interviewers grade communication, not just the answer.
Revise core CS fundamentals: OS (processes, threads, deadlocks), DBMS (indexing, normalisation, transactions) and networking basics.
Practice system design from first principles: load balancing, caching, sharding, and the CAP theorem.
Prepare 3–4 STAR stories about real projects you can speak to in depth for the behavioural round.
Practise other roles
- Frontend Developer
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- QA Lead
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- Financial Advisor
- Credit Analyst
- Auditor (Statutory/Internal)
- Company Secretary (CS)
- School Teacher
- College Professor / Lecturer
- Primary School Teacher
- Customer Service Representative
- Back Office Executive
- Operations Executive
- Logistics Coordinator
- Procurement Executive
- HR Manager
- Recruiter / Talent Acquisition
- Training Manager
- UI Designer
Software Engineer interview — FAQs
What questions are asked in a Software Engineer interview?
Common Software Engineer interview questions include: Reverse a linked list, both iteratively and recursively. Find the two numbers in an array that add up to a target sum. Detect whether a linked list has a cycle. What is the difference between a process and a thread? Interviews usually run across 4 rounds — Online assessment, DSA / problem solving, System design, Hiring manager / culture fit. Practise them with the free timed practice on this page.
How many rounds are in a Software Engineer interview?
A typical Software Engineer interview has 4 rounds: Online assessment (Timed coding problems on arrays, strings and hashing on HackerRank or HackerEarth.); DSA / problem solving (1–2 live coding rounds on data structures, algorithms and complexity analysis.); System design (Designing a scalable service (mid/senior); low-level design for early-career.); Hiring manager / culture fit (Past projects, ownership, behavioural questions and team fit.).
How do I prepare for a Software Engineer interview?
To prepare for a Software Engineer interview: Drill 150–200 DSA problems on arrays, strings, hashing, trees and graphs — pattern recognition beats memorising solutions. Always state your approach and complexity out loud before you start coding; interviewers grade communication, not just the answer. Revise core CS fundamentals: OS (processes, threads, deadlocks), DBMS (indexing, normalisation, transactions) and networking basics. Then rehearse every question out loud with the timed practice on this page before the real thing.
What skills do I need for a Software Engineer role?
Core Software Engineer skills tested in interviews include Data Structures, Algorithms, System Design, OOP, SQL, Git, Problem Solving. OnJob shows you exactly which of these skills stand between you and a 100% match on every live Software Engineer job.
Is the Software Engineer mock interview practice free?
Yes. The questions, the answer guidance and the timed practice on this page are free and need no signup. With a free OnJob account you can also take timed role tests and free certification tests. Personalised AI role and skill tests are part of the paid plans.
Ace your Software Engineer interview
Rehearse every Software Engineer question out loud on this page, then sign in to take a timed role test or a free certification in the OnJob practice hub.
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