Payments
Idempotency, ledgers and reliable money movement.
All topics · 3 lessons · 18 resources
Learn Payments on System Design Atlas
- 01How online payments workThe parties involved, why idempotency is essential, and how a ledger and reconciliation keep money correct.Core Concepts: How Things Actually Work · 9 min read · start here
- 02Design a payment systemTaking a customer's payment safely: the payment service, the ledger, retries and idempotency, asynchronous results and reconciliation.Real-World Systems · 13 min read
- 03Cross-border payments: SWIFT and foreign exchangeHow money moves between countries and currencies, what SWIFT actually is, and why international transfers are slow and costly.Real-World Systems · 9 min read
Related topics
These share a lesson with Payments.
Curated Payments resources
Case Studies
- 10 Tips for Building Resilient Payment SystemsPractical rules from Shopify's payments team: idempotency, retries, reconciliation and more.Shopify
- Architecture of NubankEdward Wible and Rafael Ferreira discuss the key elements that make Nubank tick for millions of customers every day, including transaction authorization, messaging infrastructure (Kafka), real-time double-entry accounting (Datomic), customer and temporal sharding, their analytical environment and the role of…InfoQ
- Architectures of Finance, Banking, and Payment SystemsEnabling real-time payments improves the speed of the online payment experiences to customers and allows banks to drive higher payment volumes, ideally at lower costs as well as engage new customer segments.Redhat
- Bank Backend at MonzoAt Monzo, we’re building a banking system from scratch. Our systems must be available 24x7 no matter what happens, scalable to hundreds of millions of customers around the world, and very extensible. This first post in a series about our platform explains how we’re building systems to meet these demands using…Monzo
- Billing and Payment Platform at GrammarlyGrammarly is an AI-powered communication assistant that helps more than 30 million users daily with both free and premium product offerings. This means we need…Grammarly
- Handles Millions of Digital Transactions Safely Everyday at PaytmOnline payments have become an integral part of our lives, and we are already making big waves with successful translation rates. We handle superfast, secure and reliable money transfers on a regular basis. Our transaction rate is much faster when compared with other similar businesses. Many businesses rely on us…Paytm
- Optimizing Payments with Machine Learning at DropboxIt’s probably happened to you at some point: You go to use a service for which you believe you’ve got a paid subscription, only to find that it’s been canceled for non-payment. That’s not only bad for you the customer: It causes negative feelings about the brand, it disrupts what should be a steady flow of revenue…Dropbox
- Payment Transaction Management in Microservices at Mercari* This article is a translation of the Japanese article written on June 7, 2019.—This article is the 15th day of MMercari
- Stripe's payments APIs: the first 10 yearsHow a payments API evolved over a decade, with lessons on versioning and backward compatibility.Stripe
Blogs
- Capital One BlogCapital One uses real-time data at scale, AI and machine learning, and the power of the cloud to solve challenging industry problems and build products, services, and experiences that can make a real difference in millions of peoples’ lives.Capital One
- Coinbase BlogThe engineering and technology blog of Coinbase: posts on how it designs, builds and scales its systems.Coinbase
- Designing robust and predictable APIs with idempotencyHow idempotency keys let clients safely retry payment requests without charging twice.Stripe
- Klarna BlogDisrupting the financial sector starts and ends with products that work, are easy to use and stable day after day. The Engineering competence is pivotal in creating, maintaining and developing the Klarna experience.Klarna
- Kraken BlogKraken's blog: engineering posts on platform performance, Rust backends and mobile optimisation, plus crypto education and product news.Kraken
- Monzo: How Peer-To-Peer Payments WorkBackend Engineer James Routley explains the technical work we do to help you send payments to your contacts on Monzo.Monzo
- Nubank BlogMake the extraordinary happen. Discover our success stories and careers at Nu. The Future is Purple!Nubank
- Square BlogThe Corner is Square's technical blog covering software engineering, APIs, data, open source and more.Block (Square)
- Stripe Engineering BlogAPI design, payment reliability and infrastructure posts from Stripe.Stripe