Meta Developer interview questions

The interview involved a typical face to face whiteboard question. Pretty easy question although I started off with a correct but non-optimal algorithm. Then with some help implemented a lower complexity algorithm. Apparently starting off with a non-optimal solution is not acceptable, and syntax errors are also major issues so we didn't proceed to a second round.

They came to campus for OCR. I walked into the interview room, introduced myself. He said hi, then we jumped straight into coding. His question was straight forward and I gave him the optimal solution and coded it up. I was sure to talk through the problem with him as I approached it and he told me he liked my implementation. I'm not sure why I wasn't offered a second round.