I worked briefly at a company that wrote applications that interacted with bank mainframes. Think end point bank teller systems and in branch customer/account management. They definitely do exist - every major bank has a mainframe written in (usually) cobol.
But it's very abstracted, part of our main product offering WAS abstracting it. On top of our ready to use applications, we offered APIs for higher-level data retrieval and manipulation. Under the hood, that orchestrates mainframe calls.
But even then that there could be more level of abstractions. Not every bank used screen-level mainframe access. Some used off the shelf mainframe abstractors like JxChange (yes, there's a market for this).
Fintech would be even more abstracted, I imagine. At that point you can only interact with the mainframe a few levels up, but it's still there. Out of sight.
But it's very abstracted, part of our main product offering WAS abstracting it. On top of our ready to use applications, we offered APIs for higher-level data retrieval and manipulation. Under the hood, that orchestrates mainframe calls.
But even then that there could be more level of abstractions. Not every bank used screen-level mainframe access. Some used off the shelf mainframe abstractors like JxChange (yes, there's a market for this).
Fintech would be even more abstracted, I imagine. At that point you can only interact with the mainframe a few levels up, but it's still there. Out of sight.