I worked at a no longer extant networking equipment manufacturer as an intern in college in the late 1990's. My role was to work on software for an in-development 45Gb network switch, and a bunch of the software I wrote ran on prototype boards.

Since fabricating new boards took time and was expensive, a lot of work was done to make in situ modifications that involved an insane amount of wirewrapping. One member of the team did that all day, every day as their full time job, and I was always amazed by their ability to focus consistently at that level for so long.