Butternut Box Backend Engineer interview questions

An initial chat with the internal recruiter (~1hr), Tech test (~2hrs), Tech interview (~1.25 hrs), Cultural (30mins). Then a decision is made to move you to the next round. Next round is ~2hours with some potential team members, product and one of the founders. Full process is about 7 hours and I did not receive an offer at the end. This is normally fine as not everybody is a fit for every position. I do have a problem, when after investing around 7 hours of my time, with not receiving any proper feedback other than "I wasn't 'wowed' enough" and "I'm not sure they really want the job". Everyone on the process seemed nice and I am sure it would be a nice place to work but after a much longer than usual process, I feel quite annoyed at the poor level of feedback I received which is nothing I can use to improve upon. A usual process for a position like this is a tech test, tech interview and cultural interview. This should be enough to make your decision.