Design a low-latency Payment System
Last updated: December 21, 2025
Quick Overview
Design a low-latency payment system handling millions of requests. Discuss consistency, availability, and performance trade-offs.
Walmart
System Design
Machine Learning Engineer
Walmart
December 21, 2025Machine Learning Engineer
Onsite
System Design
Easy
129
11
3,989 solved
Design a low-latency payment system handling millions of requests. Discuss consistency, availability, and performance trade-offs.
How to Approach This
- Start by clarifying functional and non-functional requirements with the interviewer.
- Estimate the scale: QPS, storage, bandwidth. This drives your design decisions.
- Draw a high-level architecture first, then deep dive into 1-2 critical components.
- Discuss trade-offs explicitly (e.g., consistency vs availability, SQL vs NoSQL).
- Address failure scenarios, monitoring, and how the system handles 10x traffic spikes.
Practice a Similar Problem on Codemia
Solve a related problem with our interactive workspace, get AI feedback, and view detailed solutions.
Solve on CodemiaSample Answer
Requirements
Functional Requirements
- Process Payments: Allow users to make payments using various methods (credit/debit cards, digital wallets, etc.).
- Transaction History: Users should be able to...
Capacity Estimation
Assuming Walmart has around 250 million unique customers and that on average, 10% of them make a payment in a day:
- Daily Transactions: 250 million * 10% = 25 million transactions.
- **Peak Load ...
Submit Your Answer
Markdown supported