PayPal coding interview
questions, leaked.
109 problems reported across recent PayPal interviews. Top patterns: array, hash table, sorting. The list below is what most candidates actually saw, plus the honest play if you can't grind all of it.
PayPal's online assessment hits you with 109 problems across a brutal mix: 70 mediums, 19 hards, and only 20 easies to warm up on. Arrays dominate at 75 problems, but hash tables (30), sorting (26), and strings (24) are your second line. You'll see Rotting Oranges, LRU Cache, Number of Islands, and Word Search in the wild. Most candidates drill the obvious patterns and choke on medium-hard hybrids. StealthCoder runs invisibly during the live OA as a safety net: if you blank on a hash-table problem mid-assessment, it surfaces a working solution in seconds, undetectable to the proctor.
Top problems at PayPal
| # | Problem | Diff | Frequency | Pass % | Patterns |
|---|---|---|---|---|---|
| 01 | Rotting Oranges | MEDIUM | 0.0 | 57% | Array · Breadth-First Search · Matrix |
| 02 | Zigzag Conversion | MEDIUM | 100.0 | 52% | String |
| 03 | LRU Cache | MEDIUM | 79.2 | 45% | Hash Table · Linked List · Design |
| 04 | Minimum Replacements to Sort the Array | HARD | 77.5 | 53% | Array · Math · Greedy |
| 05 | Count Vowel Strings in Ranges | MEDIUM | 77.5 | 68% | Array · String · Prefix Sum |
| 06 | Count the Number of Vowel Strings in Range | EASY | 77.5 | 74% | Array · String · Counting |
| 07 | Word Search | MEDIUM | 75.5 | 45% | Array · String · Backtracking |
| 08 | Number of Islands | MEDIUM | 75.5 | 62% | Array · Depth-First Search · Breadth-First Search |
| 09 | Maximum Number of Integers to Choose From a Range I | MEDIUM | 75.5 | 68% | Array · Hash Table · Binary Search |
| 10 | Maximum Frequency Score of a Subarray | HARD | 75.5 | 35% | Array · Hash Table · Math |
| 11 | Number of Valid Move Combinations On Chessboard | HARD | 75.5 | 48% | Array · String · Backtracking |
| 12 | Time Needed to Rearrange a Binary String | MEDIUM | 75.5 | 52% | String · Dynamic Programming · Simulation |
| 13 | Meeting Scheduler | MEDIUM | 75.5 | 55% | Array · Two Pointers · Sorting |
| 14 | Group Anagrams | MEDIUM | 73.4 | 71% | Array · Hash Table · String |
| 15 | Best Time to Buy and Sell Stock | EASY | 73.4 | 55% | Array · Dynamic Programming |
| 16 | Maximum Number of Integers to Choose From a Range II | MEDIUM | 73.4 | 35% | Array · Binary Search · Greedy |
| 17 | Paint House III | HARD | 73.4 | 61% | Array · Dynamic Programming |
| 18 | Minimum Non-Zero Product of the Array Elements | MEDIUM | 73.4 | 36% | Math · Greedy · Recursion |
| 19 | Smallest Greater Multiple Made of Two Digits | MEDIUM | 73.4 | 48% | Math · Enumeration |
| 20 | Count Array Pairs Divisible by K | HARD | 73.4 | 30% | Array · Math · Number Theory |
| 21 | Maximum Sum Obtained of Any Permutation | MEDIUM | 73.4 | 39% | Array · Greedy · Sorting |
| 22 | Longest Increasing Subsequence | MEDIUM | 71.0 | 58% | Array · Binary Search · Dynamic Programming |
| 23 | Maximal Square | MEDIUM | 71.0 | 49% | Array · Dynamic Programming · Matrix |
| 24 | Two Sum | EASY | 71.0 | 56% | Array · Hash Table |
| 25 | Coin Change | MEDIUM | 68.4 | 46% | Array · Dynamic Programming · Breadth-First Search |
| 26 | Product of Array Except Self | MEDIUM | 68.4 | 68% | Array · Prefix Sum |
| 27 | Pairs of Songs With Total Durations Divisible by 60 | MEDIUM | 65.5 | 53% | Array · Hash Table · Counting |
| 28 | Longest Substring Without Repeating Characters | MEDIUM | 62.0 | 37% | Hash Table · String · Sliding Window |
| 29 | Merge Sorted Array | EASY | 62.0 | 53% | Array · Two Pointers · Sorting |
| 30 | Minimum Absolute Difference | EASY | 62.0 | 71% | Array · Sorting |
| 31 | Merge Intervals | MEDIUM | 62.0 | 49% | Array · Sorting |
| 32 | Subarray Sum Equals K | MEDIUM | 62.0 | 45% | Array · Hash Table · Prefix Sum |
| 33 | Maximum Number of Events That Can Be Attended | MEDIUM | 58.0 | 33% | Array · Greedy · Sorting |
| 34 | Loud and Rich | MEDIUM | 58.0 | 62% | Array · Depth-First Search · Graph |
| 35 | Reorganize String | MEDIUM | 58.0 | 56% | Hash Table · String · Greedy |
| 36 | Find the Smallest Divisor Given a Threshold | MEDIUM | 58.0 | 64% | Array · Binary Search |
| 37 | Last Stone Weight | EASY | 53.0 | 66% | Array · Heap (Priority Queue) |
| 38 | Valid Anagram | EASY | 53.0 | 67% | Hash Table · String · Sorting |
| 39 | Meeting Rooms III | HARD | 53.0 | 44% | Array · Hash Table · Sorting |
| 40 | Top K Frequent Elements | MEDIUM | 53.0 | 65% | Array · Hash Table · Divide and Conquer |
| 41 | Sort Colors | MEDIUM | 53.0 | 68% | Array · Two Pointers · Sorting |
| 42 | Trapping Rain Water | HARD | 53.0 | 65% | Array · Two Pointers · Dynamic Programming |
| 43 | Count Vowel Substrings of a String | EASY | 53.0 | 71% | Hash Table · String |
| 44 | House Robber | MEDIUM | 53.0 | 52% | Array · Dynamic Programming |
| 45 | Random Pick with Weight | MEDIUM | 53.0 | 48% | Array · Math · Binary Search |
| 46 | Valid Parentheses | EASY | 53.0 | 42% | String · Stack |
| 47 | 3Sum Smaller | MEDIUM | 46.7 | 51% | Array · Two Pointers · Binary Search |
| 48 | Jump Game | MEDIUM | 46.7 | 39% | Array · Dynamic Programming · Greedy |
| 49 | LFU Cache | HARD | 46.7 | 47% | Hash Table · Linked List · Design |
| 50 | Longest Consecutive Sequence | MEDIUM | 46.7 | 47% | Array · Hash Table · Union Find |
Frequencies derived from public community-tagged interview reports. Click a row to view on LeetCode.
You have a week, maybe less. You can't out-grind the list above. StealthCoder runs invisibly during the actual PayPal OA. The proctor cannot see it. Screen share cannot detect it. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code.
Get StealthCoder- array75 · 69%
- hash table30 · 28%
- sorting26 · 24%
- string24 · 22%
- binary search17 · 16%
- dynamic programming16 · 15%
- two pointers16 · 15%
- greedy15 · 14%
- heap priority queue10 · 9%
- matrix9 · 8%
The distribution is punishing because arrays and hash tables aren't isolated. You'll get array problems that need prefix sums, matrix traversal that demands DFS, and string manipulation tangled with backtracking. Count Vowel Strings in Ranges and Maximum Frequency Score of a Subarray are the hidden killers: they look simple until you realize you need multiple pattern layers. Start with array fundamentals and two-pointers because they're structural; then anchor hash tables (LRU Cache is a classic design trap). Binary search and greedy appear in 17 and 15 problems respectively, so they're tertiary but non-negotiable. Dynamic programming rounds out 16 problems, mostly hiding in string and array hybrids. Don't sleep on the hard problems: they're 17 percent of the total and often the deciding factor. If you hit a wall on a greedy or backtracking problem during the OA, StealthCoder is your hedge.
Companies with similar patterns
If you prepped for PayPal, these companies recycle ~60% of the same topics.
You've seen the list.
Now make sure you pass PayPal.
Memorizing every problem above in a week is a fantasy. StealthCoder is the hedge: an AI overlay that's invisible during screen share. It reads the problem on screen and surfaces a working solution in under 2 seconds. Built by an Amazon engineer who realized the OA tests how well you memorized 200 problems, not how well you code. Works on HackerRank, CodeSignal, CoderPad, and Karat.
PayPal interview FAQ
How many array problems should I solve before the PayPal OA?+
Arrays are 69 percent of PayPal's test set (75 of 109 problems). You need 20 to 25 solid reps across basic manipulation, two-pointers, and matrix traversal. Don't just count reps; hit each sub-pattern: rotation, prefix logic, BFS/DFS on matrices. Rotting Oranges and Number of Islands are the benchmarks.
Is hash table experience enough for PayPal's medium problems?+
No. Hash tables appear in 30 problems, but most mediums combine them with other patterns. Group Anagrams pairs arrays with sorting. LRU Cache requires linked lists and design thinking. You need hash tables as a building block, not a standalone skill. Expect hybrid questions.
What topic should I study first for PayPal?+
Arrays, then hash tables. Arrays are 3x more common (75 vs. 30). Build muscle on Rotting Oranges and Number of Islands first, which also teach you matrix and DFS patterns. Then study hash tables in context: LRU Cache and Group Anagrams. This order mirrors how PayPal actually tests.
Are the hard problems worth studying before the OA?+
Yes. 17 percent of PayPal's set is hard (19 problems), and they often decide pass or fail. Minimum Replacements to Sort the Array and Maximum Frequency Score of a Subarray combine multiple patterns. Study 5 to 8 hards covering greedy, backtracking, and math. Skip the last-minute cram; this is where preparation gaps show.
How do I prepare for string and matrix problems together?+
Strings and matrices appear in 24 and 9 problems, but they often intersect (Word Search, Zigzag Conversion). Solve string problems with pattern matching first (Zigzag, Group Anagrams), then move to matrix traversal with DFS (Word Search). This mirrors PayPal's actual difficulty curve.