Pretty terrible.

Interviewers were all cold and unpleasant.

First I talked to the recruiter, which was fine. He did ask about my salary expectations only to then say that actually they have a set amount they always pay. I still am not sure if that's true or not.

They make you sign an NDA (lol) so I can't go into specifics, but there is a one hour code challenge with simple requirements that basically tests how fast you can bang out code. The interviewer said almost nothing and just told me to follow the written directions. I apparently did well on that, though.

Then a three hour interview including a ridiculous OOP design challenge where you are asked to design a class structure for an application with the vaguest, most unclear requirements you'll ever hear. It was basically designing an entire customer-facing automated sales system, including an expectation to program the movement of machines around the building (which was not explicitly communicated until there was 5 minutes left). But only the backend! Maybe. Or maybe parts of the frontend, too - you have to design the frontend, kinda, but no diagraming. Only the classes. And just pretend there is no db and everything is stored in memory, I guess?

Take that for what you will.

The recruiter told me they would get back to me in 24 hours, but after several days of nothing, I emailed him. He refused to give the decision over email and insisted on giving "feedback" by phone the next day.

That night I got a boilerplate rejection email (oopsies!) for one of the two positions they had me under consideration for (neither of which was the one I applied for and did the first two interviews for, of course). The other one remained open, leaving a bit of uncomfortable ambiguity. When I reached him, he immediately launched into telling me all the details of what they didn't like about me (my OOP design was bad lol). I don't understand how anyone would think this was an appropriate method of communication.

Can't say, NDA!