(And also why a lot of people thought that the Y2k but was over-hyped, when there was a lot of background work which fixed the problems so few people noticed when it did come to roll-over time)
Yes, lots and lots of background work went on. My grandfather made a nice chunk of cash from being able to work with some near extinct programming languages and assembly variants on obsolete machines.
But: the hypetrain wasn't so much focusing on glitches in banks and insurance companies, but on catastrophic failures in missile control software etc and embedded systems that often don't even have any concept of date.
"The Moscow rollover was the big one. The Russian military’s highly centralized command-and-control system meant that anything truly catastrophic would occur in Moscow first, then radiate outward through linked computer systems or trigger human errors farther afield. Among the Americans’ greatest fears was that a Russian missile commander might receive incorrect early-warning information from a Y2K-affected radar system; this could inspire needless retaliation."
(And also why a lot of people thought that the Y2k but was over-hyped, when there was a lot of background work which fixed the problems so few people noticed when it did come to roll-over time)