I'd argue you should be aware of the transactions and isolations levels exist, like many things, but having to recite them in an interview situation is a differ

I'd argue you should be aware of the transactions and isolations levels exist, like many things, but having to recite them in an interview situation is a different ballgame. Otherwise, you end up in the situation where every second person has a different set of pet skills and you can't hire anyone because they need to know all the skills perfectly. But it depends on what you're doing and your market. I've worked with people who took a pay cuts to go work for FAANG, after several interviews which they've studied for but I've decided it's not really needed when you're just writing a little in house CRUD webapp.