We've been looking at the payments infrastructure in New Zealand recently and have discovered that, unless you find whoever wrote something 30 years ago, most of the senior payments people have limited and ofter contradictory understanding of the capabilities of the underlying systems.
Definately the US banking systems also still have the feeling that there's been an accretion of layers of technology over ancient systems. APIs that look like XML files wrapping fixed-field-length VAX-style data. It made me wonder - are there still mainframes under there? Or mainframe software being run in emulation? Or are the systems just patchworks maintaining the 1970s interchange formats because no one can stand to making breaking changes?