Vestiaire Collective Chef De Projet interview questions

4 rounds after online application with CV and Cover letter submission - HR interview with talent recruitment on basic job details and experience - Competency based chat with manager - Technical Interview with senior tech staff - Senior interview on fit

I got to the final round and was ghosted -- this was the worst interview experience I've ever had. How can you a candidate go to the final round and then not even let them know they didn't get an offer? This was extremely unprofessional, but in hindsight it's good that I didn't get an offer from this place because it can't be a good place to work if this is what their hiring is like. Interview process was: Phone screen with a recruiter, interview with engineering manager, case study, final round with head of product