Coding questions
Mastercard Online Assessment
Overview
Here is how public prep guides and student write-ups describe the Mastercard online assessment. This is not an official company brochure.
Payments domain employer; OA is mostly coding vs bank aptitude papers.
Usual selection rounds
Rounds students usually mention: Online assessment / Codility-style coding → Technical rounds → HR/behavioral
| Item | From student reports |
|---|---|
| Platform | Codility / OA platforms reported in prep communities |
| Online test summary | Payments-tech fresher loops typically open with a coding OA then DSA/system discussions. Treat Codility mentions as community-reported, not a permanent official format. |
| Eligibility notes | Often ~7.0+ in campus filters - check your college placement email |
| Branches (reported) | CS/IT related |
Online test sections
| Section | Questions | Time | Notes |
|---|---|---|---|
| Coding OA | - | - | Confirm platform in your college placement email |
Extra notes from sources
- Check your college placement email for the platform, section order, and timing.
Sample practice question styles
These are practice questions for speed - not claimed to be from a real Mastercard live paper.
Coding Q1: First unique character
Problem: Find the first non-repeating character in a string and return its index, or -1 if none exists.
Approach: Count frequencies in one pass (hash map or array of 26 for lowercase). Second pass returns the first index with count 1.
Complexity: O(n) time
Mastercard tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q2: Stack with min
Problem: Design a stack that supports push, pop, top, and getMin in average O(1) time.
Approach: Keep a parallel min-stack (or store pairs). When pushing, also push the new minimum. When popping, pop both stacks.
Complexity: O(1) per operation amortized
Mastercard tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q3: Maximum subarray sum (Kadane)
Problem: Given an integer array, find the contiguous subarray with the largest sum and return that sum. Example: [-2,1,-3,4,-1,2,1,-5,4] → 6 (from [4,-1,2,1]).
Approach: Keep a running sum. If the running sum drops below 0, reset it to 0 before taking the next element (or track the best ending-here value). Track the global maximum as you scan once from left to right.
Complexity: O(n) time, O(1) extra space
Mastercard tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Coding Q4: Reverse a string in place
Problem: Given a mutable character array representing a string, reverse it in place without allocating another array of the same size.
Approach: Use two pointers at the start and end. Swap characters, then move inward until the pointers meet. Watch empty and single-character inputs.
Complexity: O(n) time, O(1) extra space
Mastercard tip: Restate the problem, sketch a brute-force idea, then tighten it. Call out edge cases (empty input, single element, overflow) before you write code.
Prep tips from those student reports
- Coding OA under timer
- Core CS
- Basic payments ecosystem awareness
Sources
These notes come from public reports and can differ by campus, year, and role. If your college placement email or the official careers/notification PDF says something different, follow that.
Comments & Suggestions
Related
Similar companies
Visa · PayPal · American Express · PhonePe · Stripe