TLDR; 2nd Founder interview unexpectedly cancelled, ghosted by Founder (CTO). Completed take home assignment (2hr) and was told performance was strong, and I was welcome to schedule a first 1.5hr interview. Completed first interview, was welcomed to schedule a follow-up interview with one of the founders. After scheduling the follow-up interview, the founder cancelled the appointment. I emailed both the hiring email and the founder directly. Never received a response. This is extremely unprofessional. Clearly it comes from the top down in this company, which is disappointing.