Depending on the scale of the run and innovation of the tech, it's not unusual to see a founder digging into test-run QA issues with a multimeter and soldering iron, or perhaps a serial port and software debugger. But more often in China than the US these days, or China-US partnerships. And the hobbyist Makers and home innovators still solder together one-offs a lot, that's worldwide. Speakerbox builders do a lot of projects with a little soldering.

I dare say there are more individuals who have soldered something today than there were 100 years ago.