The first company I worked for that started my career as an SWE was a small mom-n-pop shop; the wrote software for insurance companies.

I applied for a position (any position; at the time, I was still in school) and they hired and trained me as an "operator" (because I didn't have a degree, they told me, they couldn't hire me as a programmer). They put me in a small cold room with the main computer they worked on (via serial terminals) - an IBM RS/6000 AIX box. There was also a vacuum column 9-track tape drive (which they taught me how to load and use), and a large Genicom 4440 printer.

IIRC, the printer was a dot-matrix line printer, so it could fire one row of "dots" out, eventually forming the characters as the paper moved. Even in it's enclosure, it was loud, but it could rip thru a box of greenbar in no time flat.

The printer was something they sold as VAR to their clients, because it could handle multi-part carbon paper forms, like checks. We'd write programs to print to these custom forms (holding the paper up to the lights and lining up the characters with the form positions - ugh!). So, when the client used a program that printed, they were also expected to check if the printer was in the middle of a printing job, and had the write paper loaded.

Sometimes, though, we'd "dial in" to their machines to test certain code and get feedback via phone; sometimes that code was for a printer (imagine trying to debug proper printing formatting and such over a phone - hair pulling!). Well, sometimes they wouldn't check the printer before we'd run the software (even after we told them to do so). That printer would take off...

...and then we'd hear a scream over the phone for us to "stop the printer" because it would be ripping thru the box of multi-part check paper (actual physical checks with carbon copy) with whatever we were printing (generally, not checks).

Clients sometimes did this themselves as well - and eat thru an entire box of checks before they knew it; multipart check forms were (from what I understand) stupid-expensive (because they were custom printed for an individual account, not too mention the special paper they used, plus the carbon copy capability).

Ah - those were the days.

And yes, I eventually got hired as a programmer (aka SWE), before I turned 19; in between me loading tapes or running print jobs for the programming teams and such, I would also play around with learning the software they used (a variant of PICK called UniVERSE), writing small games and other such things. One of the sysadmins gave me a copy of a book on PICK to help me along, and they were "monitoring" my account. Eventually, they started handing me small tasks - "fix this bug" or "code this custom feature" - to see if I could do it.

I could, I did, and I eventually was hired, sans degree, as a programmer - and started my career that I still am doing today, as an SWE, nowadays doing SPAs using Node.js, React, and other technologies (I've lost track of the technologies and software over the years I have known, used, programmed in, etc - suffice to say, I haven't done it all, but I've carved a big chunk out, certainly).

Oh - and that place was also my introduction to Unix (via AIX on that IBB RISC platform); by the time I left that job, I knew terminfo like nobody - I had to, because we were always needing to set up clients systems with it properly to handle their serial terminals, and do it in a way that was also usable with terminal emulators on PCs, and such - it felt pretty crazy at the time).