Firefly Aerospace Engineering interview questions

I applied online and got an email back within the week from their HR Assistant that I was being reviewed as a final applicant. They offered to send me more information if I was interested( I replied for more information) and they never sent anything. A few weeks go by and I was contacted by their Senior Technical Recruiter wanting to chat with me in that same day or the next day. I replied with my availability and I never got a call. I contacted them again in a few days via email and LinkedIn and was ignored. I then contacted the HR Assistant if I was still being considered and they said they had filled the role already. The recruiting team is extremely unprofessional. They should at least have the decency to follow up on the people they promise interviews with, especially if those people reply back.