A frustrating interview experience because the questions were nonstandard (didn't get a single data structure / algorithm question). Would be fair if I was several years in industry and acquainted with this stuff, but I'm still in college and don't necessarily possess the domain knowledge yet. The person was nice enough though, but it was just a bad fit for the time being. The rejection email was an automated message. This was the part that left me with a bad impression. It's should be a courtesy to thank the candidate for interviewing with them.