These banking systems are all massively complex one off systems, often with very different sets of functions or even definitions of the problem, and the implementation details are different in almost every way possible. They’re the exact opposite of the sorts of problems modern trained AI systems are good at dealing with.
Changing data types in an interface is a boring job (didnt Office Space joke at that?) but doing this via some broken AI will probably introduce even more spaghetti.
Reality is that those systems should be killed one by one and finally when there is one system, it should be upgraded to something better. What is very difficult.
> Reality is that those systems should be killed one by one and finally when there is one system
It take so long to replace each of the systems, by the time you get to the "one true solution" 40 years have passed and you are back where you started.
Understanding semantics is required, not just form.