Implementing the PayPal “Website Payments Standard” (advanced “Buy Now button”) has proven to be an extremely painful process for me. In my opinion, they have a terribly bad system when compared to competitors and current web standards.

I’ve been implementing the Instant Payment Notification (IPN) which basically sends feedback about a “Buy Now button” transaction.

Most importantly: it has had numerous bugs and downtime the last year or so (as you can see in their sandbox status blog). Some desperate people even mentioned PayPal intentionally wanted you to test on their live system performing real payments.

Secondly, here is a list of problems they should solve or things they should improve:

• First of all, when accessing their cart, a pre-2000 JavaScript script performs a window resize. Why?
• In sandbox mode, an invalid credit card number is prefilled: you cannot use it, why prefill?
• The JavaScript page reload that is triggered after country change is a big no-no.
• You have to sign in to the developer central in a different tab or window in order to test: why?
• The whole sandbox is painfully slow (at least when accessing from Belgium).

Does this again prove that big companies suffer from their size when building products? I cannot imagine this would happen over such a long period of time in a small business.

Edit: it just happened again. You’re testing the IPN response and all of a sudden the exact same test order you made just does not work anymore. Without changing a single thing.