I've been contacted by an HR, where I've had an interview with him, then had a online technical interview, where the questions where easy/medium leetcode question, then in-person 1.5 hrs in Tel-Aviv with engineering team-lead, it included project deep-dive and hiring manager interview, it was overall good. and I've had a scheduled System Design interview (1 hr online), 15 minutes ahead of the interview it was postponed, for almost 10 days later. then again in the same day it was posponed again, having no clue when it'll be scheduled. 2-3 weeks later (a month since the last interview), I've had a rejection email included 3 reasons that I wasn't fit. is it very unrealistic, and unprofessional, they could have rejected in the very first week or two already without scheduling a System Design interview... rejecting on experience related stuff while I've had another interview scheduled is so misleading.

First, zoom meeting of 30 min with the HR in English. Second, home assignment to calc "how many ways..." in Python. They want solution that isn't complicated. So I failed....