Autodesk Senior Software Engineer interview questions

Call by recruiter, scheduled interview with manager on MS Teams. Followed by 5 rounds of interview. Position was for full stack so i had total 6 technical discussions and in each i had a system design question + 1 data structure question. Interview experience was overall good but regret i wasn't fit well because of lack of UI exposure.

Call from recruiter, manager then a screen with someone from the team. I had to do this on two occasions for two different positions with the same outcome - they don't even bother sending you a rejection email. If it is too much trouble to type a two line email, can't they at least send an automated response ?! Not sure why after I had to spend several hours through the process is it so difficult for them to do at least that.