The interviewer I had, she asked to implement a chat using websockets. Everything was implemented correctly but there was a typo with e.target.value, I had forgotten to include the "target" portion by simple slip up. Time had ran out by then. Once that was fixed everything worked, but because of that, they don't consider any of your work/effort. Personally I think it's petty for such a simple tiny mistake. Usually the interviews I've done with past companies, it's a collaborative effort but I don't see that here. So heads up.