QA is an interesting one because many companies don't separate QA from development and it works pretty well. I think the main reason you can pull this off is because you can "do QA" by writing automated tests, so it still fits into the "builder" style of work that engineers prefer.

If you asked engineers to do a large amount of manual testing, they would either (a) tell you they were and then secretly automate it, (b) simply not do it, or (c) quit.

We used to have a large QA silo at a previous job. They did exactly that. We broke that down that by moving the QA engineers into the respective product teams - and kept them, there.

Turns out many kinds of businesses/product teams (including Microsoft's Windows team, I'd say, from personal user experience) need dedicated QA people because many worthwhile tests can't really be automated well enough with a reasonable effort, or if they can, it's something that often breaks and needs regular maintenance.

I suspect that in the Windows case they simply stopped testing those troublesome cases.

Agreed. QA is really helpful for anything UX/UIrelated (where the alternative is often experimentation, which really is only good for changing already existing things, and not necessarily ideal for new things). Or if something is so big, complex, and crusty like Windows, where it’d be a Sisyphean task to go back and add automated testing everywhere it could theoretically be useful, it’s a lot better as a stopgap than idealistically declaring you don’t need QA since in theory you could automate things (if you were willing to spend 2000 person-years on it).

In case you're confused about the downvote(s):

https://news.ycombinator.com/item?id=32730380

Does Microsoft no longer have STEs and SDETs?

IIRC, the STE role was eliminated in 2006 or so.

In 2014, for most divisions, the SDET role was rolled into the function of SDEs, reportedly resulting in drastic attrition of the converted SDETs. The exception was the operating systems division, which was reported to have laid off all of its SDETs at that time.