It is a fairly standard take-home test interview process. The interviewers were professional and well-prepared.
The real problem was when they said I moved on to the final interview process and asked for dates and times to schedule the last round of the interview, then decided to ghost me for 3 days and then said they decided to do something else. You do not send a message like the following "We’ve been impressed with your journey so far and are excited about the final steps. Please use the link below to provide multiple days/times you will be available for the next round. Enter your availability now >
We want you to feel confident and ready to join our awesome team when the time comes. What questions might you have before your final interview?"
Then ghost someone for 3 days, then say, "We decided to go a different direction.". This is not how you should treat people at the end of the day; I think most people are ok with rejection, but not after you get their hopes up. It is unprofessional be wary when interviewing.