We once had a contractor who interviewed pretty well. After a while I noticed that it was impossible to have a technical discussion with him. He only took notes and never said much. I also noticed that he never delivered anything the same day. He took notes and then next morning it was done. I once told him to fix a simple bug NOW and had him sit next to me. He starred at the screen for several hours and did nothing. And not unsurprisingly it was done the next day. We came to the conclusion that he had a ghostwriter somewhere else who would do the actual work from the contractor’s notes.

Problem was that the ghostwriter was not a great dev either and wrote bad code. So we had to let him /them go. The contractor is now a principal developer/ team lead at another company……