MEMORY interview questions

I applied online using LinkedIn. Got a nice e-mail a week after, with the purpose of planning a short video call one week later. I was in the call with one of their lead engineers, after a few basic questions (like the tech stack I am working with) I had my own suite of questions, where one was about the tech used in their company for server side. I was very surprised that one of their lead engineers on front-end doesn't clearly know the server side tech they use. Not trying to make anything special about it, but I believe this is very important and somehow It shows the interest of the developers in the company they are working for. Felt strange but I moved on, since I believe the company itself has a very nice vision. The interviewer asked me to complete a coding challenge, which to my surprise had very little to do with the job description. Basically I was applying for an Android position and got asked to do some CSV reading/writing refactoring in Kotlin 🤷🏼‍♂️, something very rarely done in Android (I may be wrong, but never had to do this in my career). Even more interesting is, given that on the job description "A good understanding of algorithms and data structures and their time and space performance" was the last item and it was mentioned to be "a plus". I did the coding challenge, with the countless constraints in the exercise given by the requirement to consider the code is in production and it should be backwards compatible. I initially committed my work on the main branch (there were no specs with regards to git branching) and e-mailed them for the review. Now, the same engineer asks me to create 2 pull-requests to the main branch to make it easier for him to review the code (I thought as a lead engineer it's pretty simple to branch from a commit and make a Pull-Request if the diff is a problem, not to mention there were the commits which showed pretty clearly how the code evolved). Nonetheless, it was a piece of cake to do this myself, so I did it and created the 2 pull-requests. After more than 3 days I get an e-mail telling me along the lines "we regret to inform you that we do not have any positions that are a strong match for your experience and skills at this time". I asked for a more in-depth opinion regarding my code, because I'm always looking to improve myself. Didn't got an answer yet and I don't feel like I'll be getting one. In the e-mail it was specified something like "After careful consideration, we..." but it was quite obvious that in the entire interview and review process there was only one person dealing with my application, which is a primer in my interviewing experience and it does feel very unprofessional from a company :)