Top 30 Most Common Technical Round Interview Questions You Should Prepare For

Top 30 Most Common Technical Round Interview Questions You Should Prepare For

Top 30 Most Common Technical Round Interview Questions You Should Prepare For

Top 30 Most Common Technical Round Interview Questions You Should Prepare For

most common interview questions to prepare for

Written by

Written by

Written by

James Miller, Career Coach
James Miller, Career Coach

Written on

Written on

Jul 3, 2025
Jul 3, 2025

💡 If you ever wish someone could whisper the perfect answer during interviews, Verve AI Interview Copilot does exactly that. Now, let’s walk through the most important concepts and examples you should master before stepping into the interview room.

💡 If you ever wish someone could whisper the perfect answer during interviews, Verve AI Interview Copilot does exactly that. Now, let’s walk through the most important concepts and examples you should master before stepping into the interview room.

💡 If you ever wish someone could whisper the perfect answer during interviews, Verve AI Interview Copilot does exactly that. Now, let’s walk through the most important concepts and examples you should master before stepping into the interview room.

What are the top technical interview questions I should prepare for?

Direct answer: Focus on the fundamentals—arrays, strings, linked lists, trees/graphs, sorting/search, dynamic programming, hashing, and a handful of system-design and database questions. Below are 30 high-probability questions grouped by topic to practice and master.

  • Arrays & Strings (7)

  1. Two-sum / pairs that add to target

  2. Reverse a string / in-place modification

  3. Merge intervals

  4. Longest substring without repeating characters

  5. Container with most water

  6. Rotate array / cyclic shifts

  7. Subarray with maximum sum (Kadane’s)

  8. Linked Lists (4)

  9. Reverse a linked list (iterative & recursive)

  10. Detect cycle (Floyd’s algorithm)

  11. Merge two sorted lists

  12. Remove nth node from end

  13. Trees & Graphs (5)

  14. Binary tree traversal (inorder, preorder, postorder)

  15. Lowest common ancestor (BST & generic tree)

  16. Level-order traversal / BFS variants

  17. Graph traversal (DFS/BFS) and cycle detection

  18. Shortest path on unweighted graph (BFS) / Dijkstra basics

  19. Sorting, Searching & Complexity (3)

  20. Implement quicksort/mergesort or explain them

  21. Binary search and variations (first/last occurrence)

  22. Time/space complexity trade-offs

  23. Dynamic Programming (3)

  24. Fibonacci / memoization vs tabulation

  25. Longest increasing subsequence

  26. Knapsack / subset sum pattern

  27. Hashing & Design Patterns (3)

  28. Use hash maps for frequency/count problems

  29. LRU cache implementation (design + data structures)

  30. Design a URL shortener (basic)

  31. System Design, Databases & Concurrency (3)

  32. Design a scalable feed / messaging system

  33. SQL vs NoSQL trade-offs (indexing, joins, normalization)

  34. Basic concurrency primitives and race conditions

  35. Behavioral in Technical Rounds (2)

  36. Walk me through a technical project you owned

  37. Describe a bug you fixed under pressure — what did you change?

Why these matter: recruiters repeatedly ask variants of these problems to assess problem decomposition, code clarity, and trade-off reasoning. Practice with timed coding and mock interviews, and make each problem a template of patterns you can adapt in under 30 minutes. Takeaway: master patterns, not just solutions—recognize which pattern fits quickly.

Which algorithms and data structures should I prioritize for technical rounds?

Direct answer: Arrays, strings, hash maps, two-pointer techniques, stacks/queues, linked lists, binary trees, graphs, heaps, sorting algorithms, and dynamic programming are the highest-yield areas.

  • First 4 weeks: Arrays & strings + hash maps + two-pointer techniques — these cover the majority of entry- to mid-level problems.

  • Next 4 weeks: Trees & graphs + traversal patterns and BFS/DFS variants.

  • Following 4 weeks: Dynamic programming patterns (memoization/tabulation) and advanced greedy proofs.

  • Ongoing: Heaps, tries, union-find, and common sorting algorithms.

How to prioritize:

Practical tip: learn 10–15 canonical problems per structure (e.g., sliding window, partitioning, recursion with memoization). Use problem sets to map each question to a “pattern” (sliding window, divide & conquer, greedy). According to curated training programs, structured learning paths improve speed and retention—check guided curricula for a structured plan like those on GeeksforGeeks Academy for topic sequencing. Takeaway: prioritize patterns, not rare edge cases—solid pattern recognition wins interviews.

(Reference: GeeksforGeeks Academy for structured technical interview topic paths.)

How should I approach coding questions during a technical interview?

Direct answer: Clarify the problem, propose an approach, analyze complexity, code clearly, and test with examples.

  1. Clarify requirements and constraints — ask about input sizes, duplicates, edge cases, and expected output formats.

  2. Provide a high-level approach (e.g., “I’ll use a hash map to track frequencies and one pass for O(n) time”) and outline alternatives.

  3. State time and space complexity before coding.

  4. Write readable code with meaningful variable names; narrate as you type.

  5. Run 2–3 representative test cases including edge cases out loud.

  6. Optimize if necessary and summarize the final complexity.

  7. Step-by-step guide:

  • Problem: Two-sum

  • Clarify: Are there negative numbers? Is array sorted?

  • Approach: Use hash map to record complement index -> O(n) time, O(n) space.

  • Pseudocode → code → test on [2,7,11,15], target=9.

Example walkthrough (short):

Behavioral overlay: briefly mention trade-offs and explain why you chose one approach. Interviewers evaluate communication and trade-off reasoning as much as the final code. Takeaway: structured communication + clarity matters as much as correctness.

What system design questions are most common and how should I prepare?

Direct answer: Expect open-ended prompts like “Design a URL shortener,” “Design a scalable chat service,” or “Design a news feed.” Focus on requirements, capacity estimation, APIs, data modeling, caching, scaling, and trade-offs.

  • URL Shortener, TinyURL

  • Design a Social Feed (e.g., Facebook/Instagram feed)

  • Chat/messaging service (one-to-one, group chat)

  • File storage service (basic Dropbox)

  • API rate limiting and throttling

  • Load balancer vs API gateway usage

Common prompts:

  • Start with functional and non-functional requirements; clarify SLAs, user models, and expected throughput.

  • Sketch core components: clients, load balancers, API gateway, application layer, database, cache, messaging queue, and CDNs.

  • Discuss data partitioning, replication, and eventual consistency versus strong consistency.

  • Work through capacity planning with realistic numbers and compute read/write RPS, storage needs, and how to shard.

  • Consider trade-offs: SQL vs NoSQL, push vs pull feed, consistency, and failure modes.

  • Practice with 10–15 canonical designs and explain scaling steps (vertical → horizontal scaling, caching layers, batching).

How to prepare:

Resources: comprehensive lists of system design questions and approaches can help — community-curated collections provide 50+ starter prompts and sample solutions for practice. For deeper conceptual study and example designs, see curated system design collections. Takeaway: map requirements to architecture, justify trade-offs, and practice communicating trade-offs clearly.

(Reference: DEV Community’s collection of system design prompts for conceptual practice.)

How do companies like Google, Microsoft, and Amazon structure technical interviews?

Direct answer: They use multiple rounds that focus on coding, system design, and behavioral evaluation—expect 2–5 technical sessions plus a behavioral/culture round depending on level.

  • Google: Phone screen(s) or online coding → onsite rounds with focused coding + system design for senior roles → behavioral interviews interwoven. Emphasis on algorithmic problem-solving and clear thought process.

  • Microsoft: Coding + design + role-related technical interviews → behavioral (leadership principles vary by team). Interviewers evaluate impact and technical depth.

  • Amazon: Leadership principles heavily influence behavioral questions; technical screens test algorithms and system design based on level.

  • Startups/SMBs: Often 1–2 coding rounds plus a take-home project and cultural fit calls.

Typical patterns:

  • Research company-specific patterns: some teams prioritize timed whiteboard coding; others accept take-home tasks. Diverse sources and candidate reports provide modern patterns and expectations.

  • Tailor practice: prioritize system design for mid-to-senior roles; prioritize core algorithmic questions for early-career roles.

  • Mock interview focus: simulate company-like environments (pair-programming format, whiteboard, or timed online assessments).

Practical advice:

For company-specific mechanics and behavioral question patterns, thorough guides and candidate reports outline typical rounds and what to expect. Takeaway: match your prep to the company’s pattern—code speed for FAANG coding rounds, depth and design for senior roles.

(Reference: Tech Interview Handbook for behavioral and process patterns.)

How should I answer behavioral questions during technical rounds?

Direct answer: Use a concise framework (STAR or CAR) to structure answers: Situation/Context, Task, Action, Result. Tie technical explanations to impact and learning.

  • STAR: Situation → Task → Action → Result

  • CAR: Context → Action → Result

Frameworks:

  • Q: Tell me about a time you handled a production incident.

  • A: (Situation) Our payment service went down during a peak sale. (Task) I led triage to restore throughput. (Action) Rolled back a recent deployment, enabled circuit breakers, and implemented a temporary cache. (Result) Restored 95% throughput within 12 minutes; implemented a postmortem and a deployment safety checklist.

Sample question & answer sketch:

  • Quantify results (latency reduced, throughput improved, % error decrease).

  • Highlight your role clearly—individual contribution vs team action.

  • Discuss what you learned and what you changed to prevent recurrence.

  • Prepare 6–8 stories mapping to common competencies: leadership, teamwork, conflict resolution, ownership, and learning from failure.

Technical tips:

Resources: behavioral question banks tailored for technical roles provide sample answers and common phrasing techniques to make responses concise and evidence-based. Takeaway: structure answers with STAR/CAR, quantify outcomes, and connect technical decisions to business impact.

(Reference: Tech Interview Handbook behavioral question examples and ResumeWay for tech-focused behavioral answer guidance.)

What are the best tools and study plans to prepare for technical interviews in 2025?

Direct answer: Combine structured learning (topic-by-topic), deliberate practice (timed problem solving), mock interviews, and targeted system-design practice. Use platforms that provide curated question banks, guided courses, and live mock interviews.

  • Weeks 1–4: Arrays, strings, hash maps, sorting; daily 1–2 problems, weekly mock interview.

  • Weeks 5–8: Trees, graphs, BFS/DFS, recursion; implement traversals and practice patterns.

  • Weeks 9–10: Dynamic programming basics and pattern recognition.

  • Weeks 11–12: System design fundamentals and role-specific deep dives; practice whiteboarding or diagramming.

Recommended study plan (12 weeks example):

  • Curated guided courses and topic maps to avoid random problem selection—these accelerate progress and cover gaps.

  • Timed problem practice and code reviews to build speed and clarity.

  • Frequent mock interviews (peer or paid) to replicate pressure and get tailored feedback.

  • Role-specific projects or take-home tasks for portfolio evidence.

Tools and approaches:

Why structured paths work: guided curricula reduce wasted time and ensure depth in high-impact areas. If you want a course-like progression with technical interview topics and mock evaluation, explore structured academies and curated question lists. Takeaway: follow a consistent, time-boxed plan with regular mocks and review cycles.

(Reference: GeeksforGeeks Academy and curated developer interview lists for structured topic coverage.)

What role-specific technical questions should I study (frontend, backend, ML, DevOps)?

Direct answer: Tailor core algorithm prep with domain-specific questions: frontend focuses on browser rendering and frameworks; backend on APIs, scaling, and DBs; ML on modeling and evaluation; DevOps on CI/CD, infrastructure and monitoring.

  • Frontend (React/JS): Virtual DOM diffing, event loop, CSS layout reflows, performance optimization, component lifecycle, state management (hooks), accessibility basics.

  • Backend (Node/Java): API design, REST vs GraphQL, transactions, indexing and query optimization, caching strategies, concurrency, message queues.

  • Data Science / ML: Feature engineering, model evaluation metrics (precision/recall, ROC), overfitting mitigation, common algorithms (regression, decision trees), productionizing models, data pipelines.

  • DevOps / Cloud: CI/CD pipeline design, infrastructure as code, container orchestration (Kubernetes basics), deployment strategies (blue-green, canary), monitoring and alerting, fault tolerance.

  • Database & Storage: Normalization vs denormalization, indexing strategies, ACID vs BASE, sharding vs replication, caching layers.

Examples by role:

  • Apply a “learn + implement + explain” loop: implement a small project and be ready to explain design trade-offs.

  • Create a 6–8 question shortlist per domain to rehearse in mock interviews.

  • Practice whiteboard or diagram explanations for architecture questions.

Preparation tips:

Resource pointers: domain-specific question banks and deep-dive guides group high-value problems by role to sharpen targeted skills. Takeaway: pair core algorithm practice with role-specific projects and architecture explanations.

(Reference: GeeksforGeeks and Agilemania domain-focused question clusters.)

How Verve AI Interview Copilot Can Help You With This

Verve AI acts like a quiet co-pilot in live interviews—analyzing the question context, suggesting concise structured responses (STAR, CAR, or problem-solution-optimization), and helping you keep calm and articulate under pressure. It offers real-time hinting on problem patterns, prompts for clarifying questions, and phrasing suggestions to communicate trade-offs clearly. Use Verve AI’s live feedback to polish timing, polish your explanations, and turn practice into performance. Try Verve AI Interview Copilot for guided, contextual prompts during mock or live interviews.

(Note: This section explains how Verve AI improves live interviews by analyzing context, structuring responses, and helping users stay calm and articulate.)

What Are the Most Common Questions About This Topic

Q: What are the most common coding topics to review?
A: Arrays, strings, hash maps, trees, graphs, sorting, and DP—master patterns and typical variations.

Q: How long should I prepare before tech interviews?
A: For early-career roles, 8–12 weeks of consistent practice; mid-senior roles need ongoing system-design depth.

Q: Can I learn system design quickly for interviews?
A: Learn core components: APIs, caching, data models, and scalability; practice 8–12 canonical systems.

Q: Are mock interviews necessary?
A: Yes—simulating real pressure, feedback, and timing accelerates readiness far more than solo practice.

Q: Do companies prefer speed or readability?
A: Balance both—write correct clear code first, then optimize and explain improvements.

(Each answer is concise; use these for quick review and interview prep clarity.)

Additional resources and curated paths

  • Curated question banks and structured courses: follow topic sequences to avoid random practice. GeeksforGeeks Academy provides guided learning paths for technical interview topics that map to real company expectations. (Reference: GeeksforGeeks Academy)

  • System design prompt lists and walkthroughs: practice open-ended designs from light prompts to full capacity planning; community lists provide 50+ prompts for varied practice. (Reference: DEV Community system design list)

  • Role-specific clusters: Agilemania and other curated lists group backend, frontend, and domain-specific questions into practical sets for interview readiness. (Reference: Agilemania)

  • Behavioral question templates: build and refine 6–8 STAR stories covering ownership, conflict resolution, scaling impact, and learning from failure. (Reference: ResumeWay and Tech Interview Handbook)

Quick practice checklist before any technical round

  • Read the prompt carefully and re-state it in your own words.

  • Ask clarifying questions (inputs, constraints, edge cases).

  • Propose an approach and state complexity.

  • Implement with clean, compact code and narrate.

  • Test with examples, handle edge cases.

  • If time permits, optimize and discuss trade-offs.

  • End with a succinct summary of your solution’s strengths and weaknesses.

Conclusion

Recap: Focus your prep on high-yield algorithm and data-structure patterns, practice system design for senior roles, and prepare concise STAR/CAR stories for behavioral evaluations. Use a structured study plan, timed problem practice, and regular mock interviews to build speed and confidence. Preparation plus clear communication equals better interview outcomes. When you want contextual, real-time guidance that helps you structure answers and stay composed, try Verve AI Interview Copilot to feel confident and prepared for every interview.

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