Integration with online payment systems: howto

This is a pretty generic task for a team working on payment module for a big website. So here are some tips on how to approach this task in case you come across one.

1. Make sure you have been supplied with test data (links for staging environment, test login/password, test accounts);

2. Investigate the specifications, note: you absolutely have to clear up all possible question addressing technical support of the payment provider as early as possible. Here are examples of questions you may address: supported currencies, requirements towards all of the parameters submitted in the request, security mechanisms (for example MD5 signature when receiving back notification call), etc;

3. Create an integration prototype implementing the basic flow: submitting data to service, receiving the response/notification, make sure that you have made at least one successful transaction with your prototype, as well as checked reject/error flows (for that you need test data, mentioned in point 1)

4.  Implement integration within your system, test all possible success/reject/error flows. Make sure you take into account connection timeouts as well when for some reason provider site may become unavailable.

5. Before deploying integration functionality to production environment, get production data (links to live environment, live login/password, live accounts) and inform the provider support about the date of your deploy.

6. When going live with new provider integration, it is important to also make some live transactions using real card/wallet/voucher/bank account. Ask you business department to make such transactions, and communicate with them closely regarding the tests outcome.

And finally, enable new payment option for your users, sit back and enjoy the soaring numbers of transactions coming through. Good luck!