companies interview multiple people at the same time.
1 - During the interview process they might ghost you to speed up someone else and complete their interview as well so they can have multiple people from which they can choose the best.
2 - Very small portion but some recruiters are just aHoles, if they smell your desperation for FAANG they purposefully delay it, have seen it in other companies as well.
3 - Sometime business decision opens a requirement for the role and during your interview process this changes as well, have seen role closing in between the interview cycles. (Benefit here - was reached out by the same recruiter after a month or so, didn’t had to go through all the round from start)
4 - Due to higher no of engineers applying for the same role, they are not able to provide feedback to all the candidates.
Worst of all is when you have cleared all the rounds and all went well and got the positive feedbacks from all the interviewers. still after 3 weeks you will receive a rejection mail. With no explanation or reason whatsoever.