@mos_8502 one company I worked for at that time (one of literally the largest banks in the world - a firm that in the 1990’s talked about having $1T in assets under management) used y2k as an excuse to update internally written applications. We started the process with over 1200 internal applications (we had over 1500 full time programmers) this was in 1997/1998

They all had to test and certify their apps and all dependencies.

Unless they signed off that their app wasn’t critical

No takers

@mos_8502 in the end I wasn’t at the firm by Jan 1, 2000 (had left for another job about a year earlier) but it was impressive how seriously they took it - every app was tested and they had planned deployments and updates for any 3rd party systems that needed to be updated. This was at the height of Web 1.0 and they most definitely spent a lot on their developers and tech in general

It may have been an unusual case but also helped that when their apps failed they lost millions each hour