Had an initial chat which I felt was quite pleasant and came away from feeling positive about the next stage, which was a coding challenge. During the call, I did mention that I'd had a number of other recent interviews, all of which had included a take-home technical test or coding component and that due to the number of these samples I was being asked to produce in a short time, while I was of course happy to do one, it would have to be something I could complete within a couple of hours. The interviewer assured me there was no expectation that I would spend more than a couple of hours on their code challenge and I didn't think anything more of it.
The challenge itself was building a fairly simple API, nothing complicated, which I completed and sent back - and here's where it gets interesting. In the sample app, while I made sure to fully address the acceptance criteria of the core technical problem they described (which I won't post here as spoilers), due to the limited time I had to work on it I skipped over a few other things you would put in to a real production system such as robust validation and error handling. I annotated these cut corners in code comments, saying things like "haven't bothered to put in full error handling here, but obviously we would do this part better in a real-world system" etcetera., just to highlight that the code sample was intentionally limited and focused on their particular code challenge rather than broader features common to any fully developed system.
I was thus disappointed and surprised to hear in their feedback later that they felt this meant I "didn't demonstrate the attitude we're looking for in an employee" and they would not be taking my application any further - I've put similar disclaimers of limitation in code samples I've produced for other companies which have ultimately resulted in offers and I've never had it interpreted by anyone else as reflective of how I would build a larger system, for real world use, as a paid employee. Apparently they were actually happy enough with the technical side of the solution, they just didn't like the comments I added.
Overall, a very strange experience. Either this company completely misinterpreted what I meant by these comments (and I'll grant the language I used was very casual, maybe I should have phrased it differently than "haven't bothered" but I honestly thought the context of what I meant was clear), or our personalities are so different that we're just not a good fit for each other.