The HR Manager and the Engineering Team are very kind and professional. They prepare you for the technical part and they let you know why exactly they couldn't move forward with you

All the team members I spoke with were very friendly and well-spoken. The reason I was told I didn't get an offer was because of lack of the specific technical knowledge they were looking for. I had 5 rounds of interviews as well as a technical project, so it seems rather silly that it took that long to figure out considering I was up-front about my experience (or lack thereof) from the very beginning when I was initially recruited. My feedback to the team is this: Communicate expectations better, and improve the speed you can reject candidates to ensure we don't waste each others' time.