I've hired many people for science and automation software positions at small and large US biotechs. We usually did a phone screen (both technical and HR), then an on-site interview. The overall process wasn't much different for Ph.D. vs. Bachelors/Masters, but of course we asked very different questions depending on the level. Ph.D.-level positions were usually required to give a brief talk (partly to probe their communication skills.)

For certain specific software automation positions, we did end up giving a coding test during the on-site interview. But no homework or multi-round stuff.

The present situation in software is mostly the result of an oversupply of labor. Companies are endlessly picky because they can be. I am old enough to remember other recessions where companies could make ridiculous demands (once had a company demand I come in early Sunday morning for an interview, just to make sure I was truly committed to working 24/7. No thanks!)

Recessions eventually end, although not always in a way that helps specific careers. Good luck!