A complete system design walkthrough of Stripe's payment platform, built question by question - from requirements to production architecture. Whether you're prepping for a senior engineering interview or just want to understand how large-scale payment systems work, this is the full playbook.
Chapters
0:00 Intro - the $1.4 trillion question
0:57 The 5-step framework
1:36 Requirements - functional & non-functional
4:23 Core entities - PaymentIntent, Charge, Ledger
6:20 API design - 3 endpoints + the Idempotency-Key trick
8:30 High-level design - 8 services, built problem by problem
12:18 Deep dives - idempotency, saga pattern, webhooks & bulkhead, fraud
19:20 Conclusion - the fast-path / slow-path mental model
What you'll learn:
- How to structure a system design interview answer
- Why exactly-once charges need idempotency keys + serializable transactions
- The saga pattern for distributed transactions (and why two-phase commit fails)
- Webhook reliability with durable queues + bulkhead isolation
- Sub-20ms fraud detection with a feature store
#systemdesign #stripe #softwareengineering #distributedsystems #payments #engineeringinterviews
