There were four stages, an initial meeting with the CTO to check alignment with the role, two technical rounds which focused on both technical skills and system design/product knowledge, then an in-person values interview which was more around cultural fit.
I made it through the whole process and was communicated with quite clearly that another candidate was also being considered. They went with the other candidate for relatively fair reasons regarding industry experience. However, being told their process assessed me as mid-level rather than senior and asking if I'd like to be considered for roles of this level is downright insulting.