Occasionally there is a need to demo a payment switch to internal parties, customers, business partners, etc. Depending on the audience of the demo it is really hard to show a payment switch. How do you perform this ? I’ve seen a few methods but none that I particularly like- but this is most likely true with any data processing system- The issue is that it is hard to show something that accepts messages over the network, performs validation and business logic, send them to another endpoint and log the response, back to the caller, while handling exceptions and other considerations.
You have the toaster, stack or circle diagram that shows the “engine”, “components” and all of the modules that can be “plugged” in to support different endpoints, message formats, devices, protocols, etc. – This is actually a pretty good overview from a top-down perspective
You draw a diagram that shows a device, merchant, acquiring bank, issuing bank, gateways, endpoints, systems in play, operational processes on a whiteboard, and trace a transaction though its lifecycle typically in a different color of marker.
You login to a demo system and typically show the “UI” or User Interface of the application and run test transactions using simulators - The thing is the UI really doesn’t do much in many systems in terms of the actual processing of transactions. It is an interface to view transactions, view and set configuration options, and typically view a dashboard or status screen for monitoring purposes – these are all great things, but are only about 10% of the meat of the payment engine.
I’ve found that a combination of these three work out the best, but I get irritated that a payment switch isn’t easily demonstratable. – To me this is similar to Data Center Walk-throughs, I care more about the operational processes and procedures then by being awed by generators, battery backups, security camera, cooling systems, etc.