1) While the bank was excruciatingly bureaucratic, our systems were pretty good. We had a homogenous Windows environment, I was part of a team that maintained a single app (a big one). We did it right; we had a single environment and kept things homogenous.
Unfortunately for yours truly I work in a bank whose name was a Moravian word that is similar to a valley that is incorporated along the Danube River in Germany and is currently named something else but images of stage coaches or armored cars should give you a clearer picture. Our application environments are diverse convoluted and half the time dont comply with ordinarily recognized standards. Le Sigh.
2) If we had to talk to another system, we spent a LOT of time building a system that could interface with both our systems. For example, we had data sitting in an old COBOL mainframe, so we batched it into text files, created a parser and parsed the data. We formed a team of SME's whose job is to know and train others in that.
We use many different interconnected systems from Autosys to Xerox Mainframe Mid Range Desktop and Distributed environments none of which work well together on their own so require teams of developers and support developers to hash together code that will work in COBOL JCL ConnectDirect Autosys Perl shell scripting C++ C# Java and every other language under the sun
3) While we had too many check points, we made sure that we can trace bad code to the programmer. Trust me, we had 80+ developers working on a 1GB source code, we apportioned defects/features/projects so that we could trace who was doing what and blame them if it fails.
Our checkpoints have multiple checkpoints ( I kid you not. One of our Team Leads in the group I am in wants Line Pages ( Page sent to Pagenet that encapsulates one and only one line of the exception thrown) sent when an error occurs and Feelgood pages sent when a job runs right) Additionally he likes to obfuscate the process to the point that NO ONE knows what it is exactly that he does ( very little real work gets done by him but if an error comes out of his programs he has meetings all day long on it)
Your day to day experience with your bank is my dream come true work environment.