Navan Product Designer interview questions

The interview process was relatively standard for a design position at an established startup - phone screen with a recruiter, portfolio walkthrough with a senior designer, interview with the CPO, and a 3hr onsite. The part that I found super disrespectful was that after the onsite (which I traveled all the way from SF to Palo Alto for, so it took my entire day)....I never heard back from them. I followed up, still silence. After putting so much time and effort into the interview process, I'm astounded that they would ghost me as a candidate. I understand that they're busy, but that is very disrespectful and unprofessional.