Someone in the article's comments asked about working part time and the author responded "veterinary academia doesn’t really understand <1.0 FTE." Is the same true of FAANG-ish companies? Can you (officially) work part time in a big tech job?
The easiest way is probably being in a country that requires part time to be offered.
Before you start working somewhere you can ask for all sorts of nonstandard things.
Not sure about bigger tech, but I did a 4 day week for a bit and I'd shift the weekends, so I'd have a 4 day weekend then a day weekend then a 4, with 4 days of work between.
They scrub the toilets, serve the food, mow the campus lawns and classify pictures for the ai.