Anne Irrera:

Experienced COBOL programmers can earn more than $100 an hour when they get called in to patch up glitches, rewrite coding manuals or make new systems work with old.
 
 For their customers such expenses pale in comparison with what it would cost to replace the old systems altogether, not to mention the risks involved.
 
 Antony Jenkins, the former chief executive of Barclays PLC, said for big financial institutions – many of them created through multiple mergers over decades – the problems banks face when looking to replace their old technology goes beyond a shrinking pool of experts.
 
 “It is immensely complex,” said Jenkins, who now heads startup 10x Future Technologies, which sells new IT infrastructure to banks. “Legacy systems from different generations are layered and often heavily intertwined.”
 
 Some bank executives describe a nightmare scenario in which a switch-over fails and account data for millions of customers vanishes.