I applied through a recruiter.

First round was a rate limiter question, and the interviewer helped through the "gotcha" behind it. She was super friendly and kind. The onsite was a mess. I had one leg of the onsite, which I felt went smoothly. The interviewer even noted at the end that we had "checked all the boxes" required for the session. Their prep instructions for this interview were quite inconsistent; one part of the portal mentioned a typical DS&A question, but elsewhere, in fine print, it asked to come prepared with a pre-coded working website. Luckily, I caught that 15 minutes before the start and was able to prepare. However, the second day of interviews was very frustrating. My system design interview was postponed due to an interviewer's childcare emergency, so we rescheduled. Then, the other interview scheduled for today was abruptly cancelled a few hours later. Hours later, I received a generic email from the recruiter stating they are not moving forward. I asked for them to elaborate considering the amount of time I've taken to interview with them, to no avail. Frankly, I find this highly unprofessional. I spent significant time preparing (including setting up an environment locally for the second interview), and for the process to end this way after multiple scheduling issues is a waste of my time. I had heard reports online about Vercel having a poor recruiting process, and I'm disappointed to have experienced it firsthand.