Once done the few tests, the challenge is to find the right dialogue flow, this is the interesting part. How to make a dialogue flexible, natural and not just a simple replica of standard forms.
First start designing the flow according to the user intent, for example let the user determine what he wants to do, opening an account, buy a car or start trading on the stick with exchange. You as a dialogue designer needs to understand what a user is likely wanting to do. We could just ask with a few options, but that is not the natural way people think. Most probably some do know what kind of product they want from a bank, but some don’t. You have to cover both cases and make the dialogue flexible. This is the hard part, one user may say I want to open an account, other may say they want to buy a car and some will say I want to invest 20k in Apple shares.
Although the technology is still evolving, the understanding of human behavior and way of thinkong is even more critical. So far I have not seen banking bots offering such flexibility.