Smarter Good Development Associate interview questions

There were several parts to the interview process, a written submission, an interview with HR, then a collaboration test with other applicants. After being told that I fit the job and they would love to have me onboard in Q2 this year, it took another 2 weeks until they said that they weren't able to have me start until at least Q4 or next year. This is because they keep their applications open at all times, despite not having the role open. They then called in Q3, saying the role was available ASAP if I wanted it, which I accepted. Then after 2 more weeks of calls, they called again saying they changed their mind and decided not to proceed with the hiring. I think the delay in calls as well as how they string you along is very unprofessional.