PayPal.
Online payments, checkout, peer-to-peer transfers (PayPal, Venmo) and merchant payment processing (Braintree) across 200+ markets.
its questions lean on
- payment flows and transaction consistency
- fault tolerance (circuit breakers
- rate limits)
- object-oriented design with SOLID
- REST API design
- async processing
The rounds, as candidates describe them
- Online coding testTwo coding problems on HackerEarth.source ↗
- Problem solving, Java and databasesTwo rounds of problem solving with Java and database questions.source ↗
- System designA 45-minute HLD round for SDE2 and SDE3.source ↗
- HR and managerialBehavioural and managerial questions; senior loops may add a director round.source ↗
Reported by candidates
From public interview write-ups; each links its source.- Design a Payment SystemSystem designIP-20 · Design a Payment System →W02 · DAY 02 · Idempotency in Practice →W05 · DAY 02 · Distributed Transactions — The Saga Pattern →reported in:LeetCode Discuss · PayPal Software Engineer SDE2, Chennai (2024) ↗LeetCode Discuss · PayPal SE 3 (T24), Bangalore (2022) ↗
- Design a Payment GatewaySystem designSQ-18 · Razorpay Payment Gateway →IP-20 · Design a Payment System →W02 · DAY 04 · Webhook Delivery System →reported in:LeetCode Discuss · PayPal SE 3, Bengaluru (2024) ↗
- Design an Elevator SystemLow-level designLLD-04 · Design an Elevator System →reported in:LeetCode Discuss · PayPal Software Engineer SDE2, Chennai (2024) ↗
- Design a Calendar App like Google CalendarSystem designIP-06 · Design a Notification System →IP-17 · Design a Distributed Job Scheduler →reported in:LeetCode Discuss · PayPal Senior Software Engineer SDE3, Chennai (2024) ↗
- Design a Rate Limiter (LLD)Low-level designLLD-03 · Design a Rate Limiter →IP-02 · Design a Rate Limiter →reported in:LeetCode Discuss · PayPal T24 SDE3, June 2022 ↗
- Design a Book-Shelf Service like Goodreads (REST APIs)Low-level designW04 · DAY 01 · Caching Patterns →reported in:LeetCode Discuss · PayPal T24 SDE3, June 2022 ↗
- Design a Parking LotLow-level designLLD-01 · Design a Parking Lot →reported in:LeetCode Discuss · PayPal SDE-3, Chennai, Selected (2023) ↗
- Design a Movie Ticket Booking System (LLD)Low-level designLLD-05 · Design a Movie Ticket Booking System →SQ-16 · BookMyShow Seat Booking →reported in:LeetCode Discuss · PayPal SDE2, Hyderabad, Jun 2022 ↗
- Design a Circuit Breaker (LLD)Low-level designW02 · DAY 03 · Circuit Breakers →reported in:LeetCode Discuss · PayPal SSE, Rejected (2021) ↗
- Design an E-commerce Store (LLD)Low-level designW04 · BOSS · Design a Global E-Commerce Product Catalog System →reported in:LeetCode Discuss · PayPal SDE2, Bangalore, April 2022 ↗LeetCode Discuss · PayPal India SDE-3 (2022) ↗GeeksforGeeks · PayPal Interview Experience for SDE-3 (updated 2025) ↗
- Design a Cache with Configurable Eviction Policy (LLD)Low-level designLLD-02 · Design an LRU Cache →IP-11 · Design a Distributed Cache →reported in:GeeksforGeeks · PayPal Interview Experience for SDE-2, 3.6 Years Experienced (2021) ↗
- Design a Scalable Secrets Storage ServiceSystem designW09 · DAY 05 · Security Architecture →IP-03 · Design a Distributed Key-Value Store →reported in:GeeksforGeeks · PayPal Interview Experience for SDE-2, 3.6 Years Experienced (2021) ↗
- Design an In-Memory File SystemLow-level designno lesson for this one yetreported in:GeeksforGeeks · PayPal Interview Experience for SE 2 (updated 2025) ↗
Likely, from what they build
Our pick, not a report: questions that fit PayPal's products.- Design a Digital WalletSystem designIP-20 · Design a Payment System →SQ-01 · India's UPI →W03 · DAY 05 · Audit Log System →
Study path
Every lesson the questions above point to, once, in order.
- 01IP-20Design a Payment System
- 02W02 · DAY 02Idempotency in Practice
- 03W05 · DAY 02Distributed Transactions — The Saga Pattern
- 04SQ-18Razorpay Payment Gateway
- 05W02 · DAY 04Webhook Delivery System
- 06LLD-04Design an Elevator System
- 07IP-06Design a Notification System
- 08IP-17Design a Distributed Job Scheduler
- 09LLD-03Design a Rate Limiter
- 10IP-02Design a Rate Limiter
- 11W04 · DAY 01Caching Patterns
- 12LLD-01Design a Parking Lot
- 13LLD-05Design a Movie Ticket Booking System
- 14SQ-16BookMyShow Seat Booking
- 15W02 · DAY 03Circuit Breakers
- 16W04 · BOSSDesign a Global E-Commerce Product Catalog System
- 17LLD-02Design an LRU Cache
- 18IP-11Design a Distributed Cache
- 19W09 · DAY 05Security Architecture
- 20IP-03Design a Distributed Key-Value Store
- 21SQ-01India's UPI
- 22W03 · DAY 05Audit Log System
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