Practice · Payments

Drill the payment patterns

One concrete payment scenario per card, four options to pick from. Wrong picks come with explanations — payments is the domain where wrong picks are most expensive.

Card 1

What's the right idempotency key for this job?

Card 2

Why does this webhook controller skip CSRF?

Card 3

Trusting the redirect: what goes wrong?

Card 4

Refunded event arrived first. Now what?

Card 5

Modeling a partial refund: where does the data go?

Card 6

Wallet balance: column or ledger?

Want the theory? The six long-form Payments lessons live at Payments.

← Back to Practice Practice · Payments · 6 cards