I was asked to complete a coding challenge (groan) which is always a red flag for me. It was a live coding challenge where they asked me to pick a language I was comfortable in, so I did. But the interviewer didn't know the language at all! I was then asked to implement a sort of simple order system and talk about the solution as I went. It was really unclear as to whether I should just blindly "fill in the gaps" or restructure the code somit was testable and more aligned with solid principles etc, or just talk about what I would do and not actually implement much. The interviewer kept changing their mind on how I should proceed also. Due to the interviewer not knowing the language I wasted alot of my very short time explaining different bits of the language and why this is "thread safe" or "more efficient" whereas a proficient person would have known all that and we'd have moved on quicker. These kinds of interview always irritate me, as in what world as a developer are you asked to implement code that you've only just seen, within 20 minutes, perfectly with no time to thin.about it or understand.or.expand the requirements? If that's how these guys measure talent, then I'm out! Didn't get the job, little bit bitter of course, but its because I'd done two other interviews with this guys and it was all a bit of a waste of time as I'd only have got through this one through blind luck.