Interview Experience - 158 - PayPal | SDE2 | L2
Summary
📌 Job Role: Software Development Engineer II
🔢 Number of Rounds: 5
📜 Offer Status: Offer
📍 Location: Hyderabad, India
👤 Candidate Name: Not disclosing due to privacy
Interview Process
The interview process at PayPal consisted of 5 rounds in total:
Qualification Round – HackerEarth coding assessment with 2 questions in 75 minutes
Problem Solving Round 1
Problem Solving Round 2
System Design Round
Hiring Manager Round (Behavioral)
The journey started with a coding challenge conducted on HackerEarth. This was followed by two problem-solving rounds where the focus was strictly on optimal solutions and not brute force approaches. After that, there was a system design round, where both low-level and high-level aspects of design were tested. Finally, the process ended with a behavioral interview with the hiring manager, where resume, cloud knowledge, and career goals were discussed.
Preparation Guide
Practice solving coding problems within time limits, especially on platforms like HackerEarth, LeetCode, and HackerRank.
Strengthen core data structures and algorithms with a focus on optimization techniques.
Prepare for system design, both low-level and high-level, including database schema design and APIs.
Brush up on Java, Spring Boot, concurrency, locks, and SQL optimizations.
Be thorough with resume projects, since they will be discussed in depth.
Revise cloud technologies like AWS and GCP, and be ready to discuss full-stack development if it is part of your profile.
For the behavioral round, prepare clear answers for career motivation, work process, and teamwork experiences.
Interview Rounds
Round 1: Qualification Round
Duration: 75 minutes
Difficulty Level: Medium
Experience:
The first round was a coding assessment conducted on HackerEarth. It included two problems to be solved within 75 minutes:
Beautiful Number – Problem Link
Maximum Number of Tasks to be Performed – Reference
Both problems required writing efficient solutions within the given time frame. Time management was key since both problems were medium complexity but required attention to detail in implementation.
Key Learnings:
Practice solving coding problems under strict time constraints.
Familiarize yourself with the HackerEarth platform and its environment beforehand.
Round 2: Problem Solving Round 1
Difficulty Level: Difficult
Experience:
This round tested problem-solving depth and optimization skills. Brute force was not acceptable, and interviewers expected optimal solutions with clear explanation.
Questions included:
A coding problem applying binary search.
Backward compatibility in APIs and how to ensure it.
Linked List problem: Delete a node given only the node (no head) in O(1) time.
Array problem: Find the maximum subarray where the number of 0s and 1s are equal.
Example: Input
[1, 0, 0, 1, 1, 0, 0]→ Output:6(from index 0 to 6).
Balanced parentheses problem: Given a string like
{{{}}}{}{{}}, parse and display parentheses structure as index pairs with nesting.
Key Learnings:
Focus on optimized solutions and avoid brute force approaches.
Prepare for data structures problems (linked lists, arrays, stacks).
Be comfortable with parsing and pattern-based problems.
Be able to explain API-related concepts clearly, especially regarding backward compatibility.
Round 3: Problem Solving Round 2
Difficulty Level: Difficult
Experience:
This round was again problem-solving heavy, requiring optimal solutions and an ability to tackle advanced algorithmic problems.
Problems included:
Given an array and integer
k, count continuous subarrays whose sum is greater thank.Check if a given tree is a BST in O(1) space.
A sliding window based problem: With minimum swaps, ensure the array has sum zero (candidate couldn’t recall exact problem statement, but it was along these lines).
Key Learnings:
Practice sliding window, prefix sums, and hashing techniques.
Be prepared to optimize space complexity, especially for tree problems.
Strengthen problem-solving with arrays and subarray counting problems.
Round 4: System Design Round
Difficulty Level: Hard
Experience:
This round was focused on system design and technical depth. It tested both low-level implementation knowledge and high-level design skills.
Topics covered:
Deep dive into one of the projects mentioned in resume.
Spring Boot concepts – synchronized, Java locks, concurrency.
Java Streams and use cases.
SQL query optimization exercises.
System design for a Movie Reservation System (LLD):
Requirement gathering.
Database schema design.
APIs design.
Database locks – for example
SELECT FOR UPDATE.
Key Learnings:
Revise system design basics, especially common LLD problems.
Be well-versed with Java concurrency and Spring Boot internals.
Prepare for SQL query tuning and database locks.
Always be ready to explain resume projects in depth, from technical stack to design decisions.
Round 5: Hiring Manager Round
Difficulty Level: Medium
Experience:
The hiring manager round was a mix of behavioral and technical discussions.
Topics included:
Current company, CTC, and reason for job change.
Detailed discussion on resume projects.
Knowledge of cloud providers – AWS, GCP, and their use cases.
Process followed when given a task.
Full-stack experience and prior work on frontend development.
Key Learnings:
Be ready with a clear reason for job change and career direction.
Prepare to explain projects in depth.
Revise cloud provider basics (AWS/GCP).
Expect questions on work process, ownership, and collaboration.
Final Thoughts
The PayPal interview process was comprehensive and rigorous, covering all aspects – coding, problem-solving, system design, and behavioral evaluation.
Key takeaways for candidates preparing:
Master DSA fundamentals and practice with a focus on optimized solutions.
Practice system design, including both LLD and HLD, along with database optimizations.
Be well-prepared with Java concepts, concurrency, and Spring Boot internals.
Go through resume projects in depth since they are commonly used to frame interview questions.
Prepare for behavioral questions with clarity about career motivations, teamwork, and adaptability.
Have strong fundamentals in cloud technologies and full-stack development if relevant.
Overall, the interview process was challenging but rewarding, and the candidate successfully received an offer from PayPal.