A six-guide learning path

Payments and digital delivery

A successful redirect is not a payment record. Plan for duplicate events, retries, refunds, and customers who close the browser.

Step 1

Separate checkout redirects from payment proof

Use server-verified payment state before showing paid access or delivery.

Step 2

Use unique order and job keys so retries do not create repeated fulfillment work.

Step 3

Keep paid archives private and serve them only after checking access on the server.

Step 4

Track intended email work, retry transient failures, and suppress obsolete messages.

Step 5

Handle cumulative refund state without counting the same amount repeatedly.

Step 6

Cover the whole purchase lifecycle without charging real cards or sending production mail.

Choose one exercise and use your own project as the example. The free scorecard and interactive tools help turn reading into a next decision.