Quite a number of red flags. The technical interview who interviewed me did not show any interest in me at all when I was describing my personal portfolio. He only asked me 2 easy questions regarding React during the whole interview. When I was offered by the company with an severely underpaid salary and I was only given a day to accept it despite my effort to extend the deadline which was another red flag. Then, I decided to accept the offer within the deadline set but they chose to ignore it, rejected me and move on to next candidate even though I had comply to their requirements. Don't do this kind of thing to waste candidates' time, it says a lot the company.