TL;DR: Not professional, a very political environment with a condescending Head of Engineering. He failed me but could not specify where, offering only a vague, general answer. If it's a matter of skillset, he should be able to provide detailed feedback and allow candidates to re-interview after upskilling, which is not the case.

First, you sign an NDA while registering for the interview. I went through three rounds: one with an HR person, one with an Engineering Manager, and one with the Head of Engineering.

The HR person was pleasant to talk to and seemed to have a fair understanding of the skillset required for a management position. However, on the technology side, the experience was very unpleasant, especially with the Head of Engineering.

I felt the discussion went well with the Engineering Manager. He took notes and asked interesting questions. But when it came to speaking with the Head, I immediately felt he was looking down on me. His technical questions were very specific, and I felt he enjoyed constantly proving his superior knowledge. He then brought in the Engineering Manager I had previously spoken with, and they asked me to design a URL shortener.

I designed it, mentioning that I had never done this before and had never actually used one. So, I told them I would likely make mistakes. I came up with a solution, refining it, and ended up with what seemed like an acceptable design. The Head of Engineering left shortly after I started (so he never had a chance to evaluate my thought process), leaving me with the other manager who told me he found the design okay and that he would have done something similar.

I left with a good impression of the entire process. Then, a week later, I received a message from the HR person stating that "(...) While your track record is truly impressive, after discussion and deliberation with the team, we have decided not to proceed with your candidacy at this time (...)".

I subsequently asked multiple times for pointers on what I needed to improve to meet the company's expectations and to re-interview. Since this is about technologies, it should be very easy to tell me where I didn't meet their standards.

It took multiple texts and emails to get an answer, and all I received was "(...) the technical side is a bit lacking". They could not be more precise than that.

My overall impression is that the entire process was unprofessional. What came as a shock was my inability to reconcile the interviewers' on-the-spot feedback with the HR's final decision. The company's inability to specify which skills were lacking further reinforces this impression of unprofessionalism and potential discrimination.

Please design a URL shortener.

Talk about what you did in your career.