There's a lot of jockeying in the hiring process. You can't interview for the job you want; recruiters have to go back and forth before they even let you interview for it.

Instagram problem: Design an API for a pluggable service to allow people to make their own scheduling constraints. Build a simple XML parser.

I came in for a 5-hour onsite. I could tell right off the bat that one person was going to review me unfavorably just by the way they cooked the scenario against me. When they did not agree with my answer, they did not ask for more detail or explanation, just kind of said, "Really?" The scenarios were mostly vague and abstract; no one said what they really wanted. The hiring manager just asked very general questions about unit testing.

Grubhub had me read a ton of material that no one referenced at all. Reading it all was an even larger waste of time than the interview.

They never said why I didn't do well on the interview, something like, "Good, but not good enough. Maybe a position on another team, but those jobs are only in another state. Would you move?"

Once they are done with you, they just ghost you really fast; they can't even just give you a nice phone call. When you're in the process, they are like, "So helpful." When you're at the tail end, they won't get back to you, and you have to call them like six times to get a "no."

Then, one month later, some other recruiter cold-calls you about the jobs that supposedly only exist in NY. Big liars. They say anything to get you in, and then on the way out, they just make up lie after lie about why it's taking so long, hoping you go away.

XML parser