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43+ Deloitte questions

Deloitte interview questions and how to prepare

The questions candidates report from Deloitte interviews, sorted by how often they come up, with difficulty and topics, plus original practice written in Deloitte's interview style.

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ZorixOS tracks 43 community-reported Deloitte interview questions, drawn from an open-source dataset of real interview reports and sorted by how frequently each one comes up. Every question links to its source. Alongside them are 78 original ZorixOS practice questions written in Deloitte's known interview style (not claimed as asked at Deloitte), so you can rehearse the real format. Practice any of them out loud in a free AI mock interview tuned to Deloitte.

Updated July 2026

Deloitte interview questions candidates report

Community-reported from real Deloitte interviews (open-source dataset), most-asked first. Showing 43. Each links to its source.

  1. Climbing Stairs
    MathDynamic ProgrammingMemoization
    Easy100% asked
  2. Longest Substring Without Repeating Characters
    Hash TableStringSliding Window
    Medium100% asked
  3. Merge k Sorted Lists
    Linked ListDivide and ConquerHeap (Priority Queue)Merge Sort
    Hard100% asked
  4. Two Sum
    ArrayHash Table
    Easy100% asked
  5. Valid Palindrome
    Two PointersString
    Easy100% asked
  6. Change Null Values in a Table to the Previous Value
    Database
    Medium85% asked
  7. Add Binary
    MathStringBit ManipulationSimulation
    Easy83% asked
  8. Second Highest Salary
    Database
    Medium82% asked
  9. Best Time to Buy and Sell Stock
    ArrayDynamic Programming
    Easy79% asked
  10. Longest Palindromic Substring
    Two PointersStringDynamic Programming
    Medium79% asked
  11. Valid Parentheses
    StringStack
    Easy79% asked
  12. Longest Common Prefix
    ArrayStringTrie
    Easy73% asked
  13. Remove K Digits
    StringStackGreedyMonotonic Stack
    Medium73% asked
  14. Container With Most Water
    ArrayTwo PointersGreedy
    Medium69% asked
  15. Palindrome Number
    Math
    Easy65% asked
  16. 3Sum
    ArrayTwo PointersSorting
    Medium63% asked
  17. First Unique Character in a String
    Hash TableStringQueueCounting
    Easy63% asked
  18. Managers with at Least 5 Direct Reports
    Database
    Medium63% asked
  19. Merge Intervals
    ArraySorting
    Medium63% asked
  20. Minimum Time to Repair Cars
    ArrayBinary Search
    Medium63% asked
  21. Group Anagrams
    ArrayHash TableStringSorting
    Medium58% asked
  22. Maximum Subarray
    ArrayDivide and ConquerDynamic Programming
    Medium58% asked
  23. Nth Highest Salary
    Database
    Medium58% asked
  24. Remove Duplicates from Sorted Array
    ArrayTwo Pointers
    Easy58% asked
  25. Coin Change
    ArrayDynamic ProgrammingBreadth-First Search
    Medium53% asked
  26. Customers Who Never Order
    Database
    Easy53% asked
  27. Edit Distance
    StringDynamic Programming
    Medium53% asked
  28. Kth Largest Element in an Array
    ArrayDivide and ConquerSortingHeap (Priority Queue)
    Medium53% asked
  29. Longest Consecutive Sequence
    ArrayHash TableUnion-Find
    Medium53% asked
  30. Max Consecutive Ones
    Array
    Easy53% asked
  31. Next Permutation
    ArrayTwo Pointers
    Medium53% asked
  32. Remove K-Balanced Substrings
    StringStackSimulation
    Medium53% asked
  33. Reverse Pairs
    ArrayBinary SearchDivide and ConquerBinary Indexed Tree
    Hard53% asked
  34. Rising Temperature
    Database
    Easy53% asked
  35. Roman to Integer
    Hash TableMathString
    Easy53% asked
  36. Rotate Array
    ArrayMathTwo Pointers
    Medium53% asked
  37. Split Array Largest Sum
    ArrayBinary SearchDynamic ProgrammingGreedy
    Hard53% asked
  38. Remove All Adjacent Duplicates In String
    StringStack
    Easy49% asked
  39. Reverse Vowels of a String
    Two PointersString
    Easy49% asked
  40. Shortest Unsorted Continuous Subarray
    ArrayTwo PointersStackGreedy
    Medium49% asked
  41. Subarray Sum Equals K
    ArrayHash TablePrefix Sum
    Medium49% asked
  42. Super Ugly Number
    ArrayMathDynamic Programming
    Medium49% asked
  43. Valid Anagram
    Hash TableStringSorting
    Easy49% asked

Practice questions in Deloitte's style

Original ZorixOS questions written the way Deloitte interviews, so you rehearse the real format. Not claimed as asked at Deloitte.

  1. Imagine Deloitte's internal HR platform is experiencing intermittent performance issues impacting employee access to critical benefits information. Describe your approach to diagnosing the root cause, considering potential bottlenecks in the application layer, database, or network infrastructure. What specific tools or techniques would you employ to isolate the problem?

    Software EngineerDebugging & PerformanceTests: Evaluates systematic problem-solving skills and knowledge of distributed system debugging.

  2. Deloitte is developing a new AI-powered consulting assistant to help junior consultants with research and document summarization. Design the core architecture for this system, considering scalability for thousands of concurrent users, data security for sensitive client information, and the need for real-time response. What trade-offs would you make in choosing between different database technologies and caching strategies?

    Software EngineerSystem DesignTests: Assesses understanding of designing scalable, secure, and performant distributed systems.

  3. A Deloitte client, a large financial institution, reports that their customer-facing portal, built using Deloitte's proprietary technologies, is experiencing unusually high latency during peak trading hours. Walk me through how you would investigate this issue. What metrics would you monitor, and what steps would you take to identify the problematic service or component?

    Software EngineerDebugging & PerformanceTests: Tests ability to troubleshoot complex performance issues in a client-facing application.

  4. We are building a real-time analytics dashboard for Deloitte's internal audit team to monitor ongoing client engagements. Design the data pipeline from ingestion of audit logs to visualization. How would you handle potential data quality issues and ensure data consistency at scale?

    Software EngineerSystem DesignTests: Evaluates knowledge of data pipeline design, scalability, and data integrity challenges.

  5. Write a SQL query to find the top 5 consulting projects in the last fiscal year for Deloitte's financial services industry practice that generated the most revenue, and for each project, list the lead partner and the total number of billable hours recorded.

    Data ScientistSQLTests: Assesses proficiency in writing complex SQL queries for business reporting.

  6. Deloitte is considering launching a new service offering focused on cloud migration for mid-sized enterprises. As a Data Scientist, how would you define key success metrics for this new service? Propose an A/B testing framework to evaluate the effectiveness of a new marketing campaign targeting potential clients for this service.

    Data ScientistMetrics & ExperimentationTests: Evaluates ability to define relevant business metrics and design experimental frameworks.

72+ more Deloitte-style questions are in the free library, each practiceable live with adaptive follow-ups and an honest scorecard. Start free.

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Deloitte Interview Questions (2026) | ZorixOS