Submitted my application on their website and they sent a timed coding test the next day that was an hour long and had 2 coding problems that i did not pass.

I had a 30 minutes interview (in english) with the hiring manager. We were talking about my motivation, my previous experiences, the company and the job profile. I had a very good feeling and was really interested in that job. Afterwards I was invited to a coding challenge on Coderbyte platform: 4 exercises in one hour in basic python (lists, strings, for-loops... but nothing ML-related). I was able to solve 3 of them and had a probably minor mistake in the forth one when time was running out. Nota bene, the forth one was about binary numbers which I have last met more than 20 years ago and which has nothing to do with professional life (= obvious discrimination of older candidates). Two days later I got a rejection e-mail from a person that I don't know and without giving any reason. It was a big surprise for myself and I have absolutely no idea what went wrong. I also did not get any evaluation of the coding challenge. No respect at all, it feels like being kicked away like a piece of rubbish without even knowing why. I would have brought 15 years of experience in industry (= customer perspective) into that company where most of the employees are freshers. In addition I am fluent in three relevant languages (en, fr, ger). I offered myself for a price that was approx 80% of my previous salary in industry - that should be a rather fair deal for a start-up. Sorry I really cannot help but they should be aware that when treating excellent candidates like this they are not only loosing the candidates but also potential customers. I will never recommend this company to anybody in my CFD network.