I met a dev who's mom had been working on legacy banking systems her whole career. She had started in the eighties and she still did some urgent jobs at a crazy rate despite officially having retired.
My stepmom who retired five years ago, did COBOL dev as part of her banking job until 2002ish and then she was full-time management track. In her bank, most of the work had been integrated with Java, and the Java was done by outsourced Indian teams. At the time she retired she felt the Indian teams had been failing for years to meet objectives, and finally management was seeing it. Additionally everybody who knew the COBOL side of things was retiring at the same time as she was and she did not want to know what the system would look like in five years.