The interview was scheduled in three parts. The first part is an automated HackerRank. The first three questions are about LeetCode Medium level, and the last part is you coding a binary classification neural network with limited access to an LLM. The time limit is about 24 hours, and it took me about 6-7 hours in total. The second part is an introduction/cultural fit part, which generally went pleasantly. I asked them about the test, which seemed a bit too hard/FAANG-level. They explained that they don't have an HR team, and that they need to filter an enormous amount of candidates before they can proceed. Then, I was given a take-home assignment, the essence of which was to produce a report for advertisement expenses, and to do some predictive modelling for it. There were specific individually challenging parts of the assignment, and the scope for the tasks was quite broad. I managed to finish it in a day of full concentrated effort. Despite that, I got a generic, zero-information rejection letter. Given the substantial difficulty of the initial assessment and the amount of time and brainstorming the take home took, giving a bland and generic one-liner rejection letter strikes me as disrespectful. I understand not giving feedback on the initial stages of the process due to not having an HR team, but this stops being a valid reason by the time a candidate has spent substantial amounts of time and effort on a non-trivial take-home task. EDIT: I was later reached out by phone and was given an explanation as to why a rejection happened. I was due to some internal processes and decision-making that I'd rather not mention, though in general they were satisfied with the quality of my take-home. The one-liner is just their ATS system not being configured properly. Oh well.