I had an initial interview that went well enough to progress me to the next round. For the next round I spent a significant amount of time preparing for a presentation the interviewers asked for. The interview called for a "15-minute presentation on a technical subject I am deeply familiar with", which is extremely vague and lacks any direction. I asked for clarification and they said to choose any topic I consider myself an expert in, which did not help much but alas I still created and rehearsed my presentation. Less than 24 hours before my second interview, I was informed that they had filled the position and they cancelled my interview without even giving me the courtesy of a phone call. I would be wary when interviewing with this company.

This was a few years ago, but I remember I had a phone call either with HR or a recruiter. Later I got invited on-site for a technical one. It was one of my first interviews after I graduated. I didn't get the job, but I feel I learned a lot from the process.