I was contacted by a recruiter on LinkedIn. After some dialog on LinkedIn, I talked to a recruiter on the phone a few times. He was friendly and engaged. Then things went bad. I was emailed by someone else asking if I'm interested in the job any more, as they didn't receive my "pre-work". They never sent it, so they re-sent it. They wanted me to write some automated tests on a platform that was familiar, but still new to me. At that point, I realized I was doing hours of pre-work for no pre-pay. I withdrew on principle. All my other jobs never had pre-work. There was a company that was scamming candidates by basically making them do work, and then taking & using their work unpaid(and not getting the job). I was not about to repeat that.