Paypal Software Engineer Onsite Coding Questions
33+ questions from real Paypal Software Engineer Onsite Coding rounds, reported by candidates who interviewed there.
What does the Paypal Onsite Coding round test?
The Paypal onsite coding round is the core technical evaluation. Software Engineer candidates typically see 2-3 algorithm and data structure problems. Problems range from medium to hard difficulty, and interviewers evaluate both correctness and code quality.
Top Topics in This Round
Paypal Software Engineer Onsite Coding Questions
I\'m having trouble understanding how to solve the following problem: (Appreciate any help with the logic) Problem: You are given a list[list[str]] which represents boarding passes for an itinerary. You optimized...
You have N coins. All are the same weight except for one, which is either heavier or lighter than the others. Design an efficient algorithm to identify the counterfeit coin....
LeetCode #1200: Minimum Absolute Difference. Difficulty: Easy. Topics: Array, Sorting. Asked at PayPal in the last 6 months.
#300 Longest Increasing Subsequence
LeetCode #300: Longest Increasing Subsequence. Difficulty: Medium. Topics: Array, Binary Search, Dynamic Programming. Asked at PayPal in the last 6 months.
#33 Search in Rotated Sorted Array
LeetCode #33: Search in Rotated Sorted Array. Difficulty: Medium. Topics: Array, Binary Search. Asked at PayPal in the last 6 months.
#3 Longest Substring Without Repeating Characters
LeetCode #3: Longest Substring Without Repeating Characters. Difficulty: Medium. Topics: Hash Table, String, Sliding Window. Asked at PayPal in the last 6 months.
LeetCode #295: Find Median from Data Stream. Difficulty: Hard. Topics: Two Pointers, Design, Sorting, Heap (Priority Queue), Data Stream. Asked at PayPal in the last 6 months.
LeetCode #347: Top K Frequent Elements. Difficulty: Medium. Topics: Array, Hash Table, Divide and Conquer, Sorting, Heap (Priority Queue), Bucket Sort, Counting, Quickselect. Asked at PayPal in the last 6 months.
#56 Merge Intervals
LeetCode #56: Merge Intervals. Difficulty: Medium. Topics: Array, Sorting. Asked at PayPal in the last 6 months.
LeetCode #2858: Minimum Edge Reversals So Every Node Is Reachable. Difficulty: Hard. Topics: Dynamic Programming, Depth-First Search, Breadth-First Search, Graph Theory. Asked at PayPal in the last 6 months.
LeetCode #1251: Average Selling Price. Difficulty: Easy. Topics: Database. Asked at PayPal in the last 6 months.
#3820 Pythagorean Distance Nodes in a Tree
LeetCode #3820: Pythagorean Distance Nodes in a Tree. Difficulty: Medium. Topics: Tree, Breadth-First Search. Asked at PayPal in the last 6 months.
#735 Asteroid Collision
LeetCode #735: Asteroid Collision. Difficulty: Medium. Topics: Array, Stack, Simulation. Asked at PayPal in the last 6 months.
#560 Subarray Sum Equals K
LeetCode #560: Subarray Sum Equals K. Difficulty: Medium. Topics: Array, Hash Table, Prefix Sum. Asked at PayPal in the last 6 months.
#121 Best Time to Buy and Sell Stock
LeetCode #121: Best Time to Buy and Sell Stock. Difficulty: Easy. Topics: Array, Dynamic Programming. Asked at PayPal in the last 6 months.
Implement a simple banking system simulation with the following operations: 1. `createAccount(accountId: str, timestamp: int)`: Create a new account. 2. `deposit(accountId: str, amount: int, timesta
Implement LRU Cache
Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and put. - get(key) - Get the value (will always be positive) of the key if t
Maximum Subarray Sum
Given an integer array nums, find the contiguous subarray (containing at least one number) which has the largest sum, and return its sum. Example: ```plaintext Input: nums = [-2,1,-3,4,-1,2,1,-5,4]
Given a binary tree and two nodes, find the lowest common ancestor of the two nodes. Nodes are represented by different values in the binary tree. You can assume all node values are unique in the tree
Binary Search Tree Pruning
Given a binary search tree (BST), remove all nodes whose key values are less than a given value from the tree. The subtrees of the removed nodes are also deleted. ### Input Description - `root`: the
What to Expect in the Paypal Onsite Coding Round
The Paypal Software Engineer Onsite Coding round has a specific calibration purpose distinct from other rounds in the loop. Across 33+ verified reports on LeakCode for this exact round type, the consistent expectations: clear scoping of the problem before diving into a solution, explicit reasoning about complexity, structured handling of edge cases, and the ability to discuss trade-offs between two reasonable approaches.
Reports tagged with the Onsite Coding round at Paypal show recurring patterns in difficulty and topic distribution. The Onsite Coding round is typically 45-60 minutes; the interviewer is calibrated against a specific rubric. The discriminator between candidates who advance and candidates who do not is rarely the final correctness of the answer. It is the path: did you clarify, did you verbalize your approach, did you handle edge cases, and did you communicate throughout.
How To Prepare for This Specific Round
Filter the questions below to the most recent reports (past 6-12 months). Questions tagged for this exact round type from this exact company at this exact role level are the highest-signal data available. Older reports may reference questions that have since rotated out of the company's pool.
Practice 4-6 representative problems from this set under timed conditions. The goal is not memorization (companies rotate questions); the goal is to internalize the patterns the interviewer typically reaches for and the depth of follow-up to expect. Reports on LeakCode also tag the typical follow-up depth at this round type, which is the discriminating signal between hire and no-hire calibration.
Onsite Coding Round Timing and Format
The Onsite Coding round at Paypal typically runs 45-60 minutes. Use the first 2-3 minutes to clarify requirements; you should never start coding or designing without verifying the input/output format, constraints, and edge cases out loud. Use the next 5-7 minutes to verbalize your approach before writing any code. The middle 20-30 minutes are implementation. Reserve the final 10 minutes for testing with concrete examples and discussing optimization or trade-offs.
Time budget discipline is one of the most reliable senior-vs-junior discriminators in this round. Strong candidates verbalize where they are in their budget out loud ("I've used about 20 minutes, I have 15 minutes left for testing and one optimization"). This signals engineering maturity to the interviewer and creates positive feedback they can capture in writing.
Common Failure Modes in This Round
Reports tagged "no hire" at Paypal Software Engineer Onsite Coding commonly cite: coding silently without verbalizing approach, jumping to implementation before clarifying requirements, missing edge cases (empty input, single element, very large input), producing working code that the candidate cannot refactor when asked, and failing to test their solution with concrete examples before declaring done.
The single most predictive failure mode in 2025-2026 reports: not asking clarifying questions. Interviewers at all FAANG companies are explicitly trained to weight this dimension. Strong candidates ask 3-5 clarifying questions even on problems that look obvious; weak candidates dive into code immediately. The clarifying-question check is often the first signal recorded in the interviewer's notes.
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