Unprofessional recruiters: They call without prior notice and do not respond to emails or phone calls. If you do not wish someone to call you, why share your number? I could not reach my recruiter when I had a serious technical problem during my interview. Whom was I supposed to reach out to?

Scheduling of the final interviews was extremely bad. You cannot expect people to give final interviews with only 24 hours' notice. The recruiter disappeared after I could not schedule my interview immediately.

The final interview was extremely hurried (after one of the interviewers could not connect to the interview for a good 15 minutes). They kept pushing me to write code before I could come up with a solution. The difficulty of the interview also varies wildly.