Seaplane IO interview questions

Application Applied online through and got an interview invite a few days later. Interview In the first part of the interview, I met one of the co-founders and had a lovely conversation. The second interview was to assess my technical skills and a technical assessment. I completed the assessment and submitted my solution. After a day I received an email "Thank you for taking the time to complete the assigned task. Unfortunately, we have decided not to move your application forward at this time. There are a lot of companies hiring so we really appreciate that you chose to consider us. We wish you every success with your job search. Thanks again for your interest in Seaplane. All the best" When I asked what led to the decision was told that my implementation was incorrect.

First round was an HR-style screen with the CEO. Secondly was a coding test, as described in the other review posted here. Took a while to do but the programmers at the company took the time to engage with me and answer my questions, so all in all this was a good experience. Following this there was a tech interview, similarly enjoyed this. Final stage was a call with the CTO, where I wasn't really asked any questions, didn't really get a word in either. No offer followed this, but no real explanation. After getting to that stage and investing that much time in the process I would have appreciated some feedback.