Etsy Software Engineer New Grad interview questions

coding challenge (work sample style interview), 20 min behavior interview with recruiter, 4 hour onsite (2 technical rounds working on single work sample interview, 1 round with engineering manager, closing interview with HR). They took a WEEK to get back to me after the final onsite. The rejection was from a no-reply email, so I couldn't even ask for feedback. Very unprofessional considering how much time I had sunk into this application.