here is the whole loop for a print on demand shop with no backend of its own. three parties, one function, and a webhook to tie it off.
the loop
- the catalogue lives in printify. it knows the products, the variants and the print cost
- the storefront reads that catalogue and shows it
- a customer checks out through stripe
- stripe fires a webhook on a paid order
- a serverless function catches it and places the fulfilment order with printify
no inventory, because the items are made to order. no warehouse, because the print partner ships them. no medusa, because there is nothing standing up that needs a server to run it.
where the care goes
the loop is simple but the edges are not. you handle:
- the webhook signature, so only stripe can trigger fulfilment
- idempotency, so a retried webhook does not place the order twice
- the failure case, where payment clears but fulfilment is rejected
get those three right and the rest is plumbing. the shop costs almost nothing at rest and only does work when a real order comes in.