Recruiter was ridiculously slow and / or unresponsive. I sent 3+ emails asking for my first interviewer's email so I could personally thank them, or for her to pass forward my thanks. Not a single time did she respond to any of my emails or confirm - the only times she ever replied to me was because I was direct replying to one of her emails, and even then she'd respond 3 days (minimum!) to a week later. On a Monday I asked to switch the 2nd round phone interview from that week Friday to next week's Thursday. She responded that same Friday an hour before the interview, and the interviewer called anyway because my recruiter clearly didn't contact them. Extremely unprofessional. I declined to continue with the interview process after that because communication was so lacking and frustrating.