They stick with COBOL because it runs well on the mainframe. The mainframe and sysplex architecture gives them an absurd level of stability and virtualization that I don't think the rest of the market has nearly caught up to yet. Plus having a powerful and rugged centralized controller for all of this is very useful in the banking business model.

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Betelbuddy 2 hours ago | parent [-]

This is the reason. IBM Mainframe business grew 60%. The modern mainframe is the best state of the art platform for computing, in both reliability and efficiency.

	▲	ASalazarMX an hour ago \| parent [-]
		Also, IBM mainframes are wonderfully isolated from physical hardware. They could change processors in the next model, and users would notice a small delay as binaries were recompiled on-the-fly the first time it was used. They surely could extract more performance from the hardware by shedding layers, but prioritized stability and compatibility.