Payment system integration is a challenging, time-consuming and labor-intensive task. Any company that wants to integrate with a payment processor has to go through several important steps. Payment system integration is a process that requires much time, resources and efforts. Naturally, development resources for payment system integration must be allocated, but before the actual development can start, the integrator business must obtain a lot of information and resources from the processor it is integrating with. Particularly, a certification agent must be assigned by a processor to supervise the integration process. The processor must also provide specifications, test credentials, test cards and test scenarios, as, before the application actually works, a lot of testing has to be done.
Some companies prefer to start payment system application development once they get specifications from the processor, but, in such cases, when the testing starts, it might turn out that huge parts of the software must be rewritten. Consequently, in order to save development efforts, it is recommended to start testing (especially, connectivity testing and basic transaction processing tests) with a basic prototype, and only then proceed to the actual application development process. In this way the integrator can make sure that the application will function properly when it comes to real transaction processing.
Another general recommendation for businesses, planning payment system integrations, is to perform application testing on specially designed certification scenarios, which can be run automatically (as opposed to random test examples\transactions\cases modeled manually). This approach might prove extremely effective when hundreds or thousands of test scenarios must be certified.
An article providing a detailed description of payment system integration steps is available at paylosophy.com web-site.