People I know who work and have worked for M$ tell me Jerry (barnacules) was a SDET (Test Engineer) which is essentially the lowest development role you can have with the company.
It's like entry level stuff where you don't need a lot of dev experience and do a lot of cutting and pasting. I am astonished M$ kept him employed for 15 years. He must have been good at staying under the radar, or worked in decent dev teams. Either way, his clickbait windows 10 rants give him plenty of YouTube views.