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46+ EPAM Systems questions

EPAM Systems interview questions and how to prepare

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

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ZorixOS tracks 46 community-reported EPAM Systems 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 EPAM Systems's known interview style (not claimed as asked at EPAM Systems), so you can rehearse the real format. Practice any of them out loud in a free AI mock interview tuned to EPAM Systems.

Updated July 2026

EPAM Systems interview questions candidates report

Community-reported from real EPAM Systems interviews (open-source dataset), most-asked first. Showing 46. Each links to its source.

  1. Longest Substring Without Repeating Characters
    Hash TableStringSliding Window
    Medium100% asked
  2. Merge Sorted Array
    ArrayTwo PointersSorting
    Easy100% asked
  3. Move Zeroes
    ArrayTwo Pointers
    Easy100% asked
  4. Two Sum
    ArrayHash Table
    Easy100% asked
  5. Minimum Operations to Make a Uni-Value Grid
    ArrayMathSortingMatrix
    Medium94% asked
  6. LRU Cache
    Hash TableLinked ListDesignDoubly-Linked List
    Medium89% asked
  7. Valid Parentheses
    StringStack
    Easy88% asked
  8. Longest Common Prefix
    ArrayStringTrie
    Easy85% asked
  9. Longest Palindromic Substring
    Two PointersStringDynamic Programming
    Medium83% asked
  10. Valid Anagram
    Hash TableStringSorting
    Easy81% asked
  11. Best Time to Buy and Sell Stock
    ArrayDynamic Programming
    Easy77% asked
  12. Group Anagrams
    ArrayHash TableStringSorting
    Medium75% asked
  13. Rotate Array
    ArrayMathTwo Pointers
    Medium75% asked
  14. 3Sum
    ArrayTwo PointersSorting
    Medium65% asked
  15. House Robber
    ArrayDynamic Programming
    Medium65% asked
  16. Longest Consecutive Sequence
    ArrayHash TableUnion-Find
    Medium65% asked
  17. Partition Equal Subset Sum
    ArrayDynamic Programming
    Medium65% asked
  18. Reverse String
    Two PointersString
    Easy65% asked
  19. Reverse Vowels of a String
    Two PointersString
    Easy65% asked
  20. String Compression
    Two PointersString
    Medium65% asked
  21. Trapping Rain Water
    ArrayTwo PointersDynamic ProgrammingStack
    Hard65% asked
  22. First Unique Character in a String
    Hash TableStringQueueCounting
    Easy63% asked
  23. Generate Parentheses
    StringDynamic ProgrammingBacktracking
    Medium63% asked
  24. Merge Intervals
    ArraySorting
    Medium63% asked
  25. Add Two Numbers
    Linked ListMathRecursion
    Medium55% asked
  26. Count Salary Categories
    Database
    Medium55% asked
  27. Counter
    Easy55% asked
  28. Duplicate Emails
    Database
    Easy55% asked
  29. Edit Distance
    StringDynamic Programming
    Medium55% asked
  30. First Missing Positive
    ArrayHash Table
    Hard55% asked
  31. Kth Largest Element in an Array
    ArrayDivide and ConquerSortingHeap (Priority Queue)
    Medium55% asked
  32. Maximum Difference Between Node and Ancestor
    TreeDepth-First SearchBinary Tree
    Medium55% asked
  33. Maximum Subarray
    ArrayDivide and ConquerDynamic Programming
    Medium55% asked
  34. Multiply Strings
    MathStringSimulation
    Medium55% asked
  35. Palindrome Number
    Math
    Easy55% asked
  36. Pow(x, n)
    MathRecursion
    Medium55% asked
  37. Reverse Integer
    Math
    Medium55% asked
  38. Reverse Linked List
    Linked ListRecursion
    Easy55% asked
  39. Reverse Words in a String
    Two PointersString
    Medium55% asked
  40. Roman to Integer
    Hash TableMathString
    Easy55% asked
  41. Sort Characters By Frequency
    Hash TableStringSortingHeap (Priority Queue)
    Medium55% asked
  42. Top K Frequent Elements
    ArrayHash TableDivide and ConquerSorting
    Medium55% asked
  43. Two Sum II - Input Array Is Sorted
    ArrayTwo PointersBinary Search
    Medium55% asked
  44. Unique Paths
    MathDynamic ProgrammingCombinatorics
    Medium55% asked
  45. Median of Two Sorted Arrays
    ArrayBinary SearchDivide and Conquer
    Hard53% asked
  46. Merge Two Sorted Lists
    Linked ListRecursion
    Easy53% asked

Practice questions in EPAM Systems's style

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

  1. EPAM helps clients build large-scale enterprise solutions. Imagine you're building a new feature for EPAM's internal project management tool to track developer hours across thousands of concurrent projects. Design the database schema and explain how you would handle potential race conditions when multiple users try to update the same project's hours simultaneously.

    Software EngineerDatabase Design & ConcurrencyTests: Evaluates understanding of database design principles for large-scale systems and knowledge of concurrency control mechanisms.

  2. EPAM often deals with migrating legacy systems to modern cloud architectures. Describe the challenges you'd anticipate when migrating a monolithic Java application with a complex database to a microservices architecture on AWS. Focus on data migration and inter-service communication strategies.

    Software EngineerSystem Design & Cloud MigrationTests: Assesses ability to design and strategize for complex system migrations, considering trade-offs and potential pitfalls.

  3. EPAM's clients operate in diverse industries. Suppose a client in the financial services sector is experiencing slow API response times for their core trading platform, which is built using EPAM's typical enterprise stack. How would you approach debugging this performance bottleneck, starting from the user's complaint to identifying the root cause?

    Software EngineerDebugging & Performance OptimizationTests: Tests systematic debugging skills and knowledge of performance analysis techniques in a complex application environment.

  4. EPAM often builds custom analytics dashboards for clients. You've identified a bug in the reporting module where daily active user counts are being inflated due to incorrect session aggregation logic. Write a Python function to correctly calculate DAU from a log stream containing user IDs and timestamps, and explain your test cases.

    Software EngineerCoding & Data ProcessingTests: Measures coding proficiency, logical reasoning for data aggregation, and understanding of testing methodologies.

  5. EPAM develops solutions for global clients. Consider a scenario where EPAM is developing a content delivery network (CDN) for a media streaming client. Design a caching strategy to minimize latency and maximize throughput, considering factors like content popularity, geographic distribution of users, and cache invalidation.

    Software EngineerSystem Design & Distributed SystemsTests: Evaluates understanding of distributed systems concepts, specifically caching strategies for high-throughput, low-latency applications.

  6. EPAM's consulting often involves recommending technology stacks. For a new client in the e-commerce space looking to build a scalable recommendation engine, what core technologies would you recommend and why, considering factors like real-time processing, data volume, and cost-effectiveness?

    Software EngineerTechnology Recommendation & System DesignTests: Assesses knowledge of current technology trends and the ability to make informed technology choices based on client requirements.

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

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EPAM Systems Interview Questions (2026) | ZorixOS