It is a horrific drag on the team to have the wrong engineer in a seat.
If we can’t sus out who is cheating and who is legitimate, then the only answer is that we as a field have to move towards “hire fast, fire fast.”
Right now, we generally fire slow. But we can’t have the wrong engineer in a seat for six months while you go though a PIP and performance cycle waiting for a yearly layoff. Management and HR need to get comfortable with firing people in 3 weeks as opposed to 6 months. You need more frequent one-off decisions based on an individual’s contributions and potential.
If you can’t fix the interview process, you need more PIP culture.