I've been out of the industry for more than 20 years now, a lot has happened in that time though that world does not move as fast as the software world I definitely would not say I know it 'inside out' (and probably never did in the first place). Machinists dedicate their lives to the work, I merely passed through and learned just enough of the domain to be able to do my job.

The customers were super interesting, from a lathe that worked gold for watch cases (where the repeat accuracy was probably less important than the degree to which the machine managed to recover the cuttings) to one that turned wheels for harbor cranes and everything in between.