PayPal Software Engineer Interview Experience
PayPal · Mid level
Interview process
The overall interview process was smooth and well structured. It started with the online assessment, followed by technical interview rounds focused mainly on DSA and problem-solving. The interviewers also asked follow-up questions to understand how I approached the problem and how I would optimize the solution.
What went well was that I was able to explain my thought process, discuss different approaches, and arrive at optimized solutions for most of the problems. The interviewers were also helpful and gave enough space to think through the problems.
What didn’t go as well was that I could have managed my time better during the follow-up questions. I spent a little too much time explaining the initial approach, which left less time for some of the follow-ups. Overall, it was a good learning experience and gave me a clear idea of the areas I need to improve.
Interview rounds · 2
- 1
Online assessment
TechnicalQ1. 1. Question: Given an array of integers, find the length of the longest contiguous subarray that contains at most two distinct numbers.
How they answeredI used a sliding-window approach with a HashMap to keep track of the frequency of each number in the current window. I expanded the right pointer and whenever the window contained more than two distinct numbers, I moved the left pointer until it became valid again.
The time complexity was O(n) and the space complexity was O(n).
- 2
Phone screen
TechnicalQ1. You are given a string containing lowercase English letters. Find the length of the longest substring without repeating characters.
How they answeredsolved this using a sliding window and a HashMap storing the most recent index of every character. When I encountered a character that was already present in the current window, I moved the left pointer to one position after its previous occurrence.
For example, for "abcabcbb", the longest substring without repeating characters is "abc", so the answer is 3.
The time complexity was O(n) and the space complexity was O(k), where k is the number of distinct characters.
Tips from the candidate
I would recommend focusing on DSA fundamentals, especially arrays, strings, hash maps, sliding window, two pointers, trees, and graphs. Practice explaining your approach clearly before jumping into the code, and be prepared for follow-up questions where the interviewer asks you to optimize the solution or handle edge cases. I would also revise basic OOP, system design fundamentals, and be comfortable discussing projects from your resume.
Company culture
The interview process felt structured and the interviewers were approachable. I liked that they focused not only on getting the correct solution but also on how I approached the problem, communicated my thinking, and handled follow-up questions. The overall interaction felt professional and collaborative.