Level 6: Applied: cases, FDE scenarios, mocks · L6.2 Classic cases II
Payment system
Design idempotent payments, a ledger and reconciliation.
15 min · Pro
What you take away
- At 58 payments a second this is not a scale problem; the whole difficulty is that an external call can time out ambiguously.
And 3 more inside the class, in Pro.
How the class is laid out
- The prompt
- Requirements and the numbers
- The design
- Three decisions
- The twist
- Check your understanding