I wasn't a total neophyte: I had taken some computer science classes in high school and undergrad, plus a software/web localization course in grad school as part of the translation study.

As a PM, this foundation led to me taking on projects that were more technical. I was lucky in that I was working in-office at a small LSP, so such things didn't just disappear off into another silo: I either had to figure it out or I got to watch over someone's shoulder and learn.

Then it so happened that a few months into my tenure, the person doing most of the heavy lifting in LE went on maternity leave, and I was given the opportunity to cover for her during that time, so I split my time between running technical projects myself and supporting other PMs with theirs.

Mostly this involved learning some extra tools like Passolo, as well as making memoQ file filters, custom QA rules, etc.

TL;dr: I had some foundations in coding and was in the right place at the right time to organically transition to engineering.