Momenta(NH) interview questions

I'll say this first: I was completely ghosted after interviewing twice in person after an initial phone screening. No email telling me I'm not in the running, no email or phone call saying they chose another candidate. Nothing. Highly unprofessional and rude to ask so much of interviewees without so much as a follow up or thanking them for their time even if they didn't get the job. Lengthy process, maybe because of company size. Started with 30 minute interview via phone with HR person. HR person emailed me saying they would be late to call me, and called 30 minutes later than scheduled. Followed up with me via email that same day to schedule first in-person interview. Went to interview 3 days after phone interview and sat with 4 people at the same time. Everyone I met was friendly enough. I was contacted the same day for second in-person interview the next week with the same exact people, all at the same time again. Why? I don't know. Owner of the business was late to that 10 AM interview. The second interview ended and before I could even shake everyones hand, they were gone from the room. I felt very rushed off at the end, the HR person didn't even make herself available to shake my hand. It felt like the interview went OK, especially since they wanted to meet with me in person twice, but I did not hear from anybody at that company afterwards. Not a note saying they filled the position, a note saying they've chosen to explore other candidates, nothing. This is the first company I have ever had this experience with. Disappointing, as their product is interesting and their location is great.