There's another one: 5) You might be a good programmer but your skillset in terms of technology stack(s) might not match up with what employers/recruiters are

There's another one: 5) You might be a good programmer but your skillset in terms of technology stack(s) might not match up with what employers/recruiters are looking for. We interviewed a junior dev a couple of years back who had exclusively RPM and mainframe experience. We're a .NET/C#/SQL Server/TypeScript/React shop, with a bit of R and Python thrown in outside of the core technology team. I couldn't work out whether he couldn't get his head round our pair programming task (which isn't any kind of ridiculous invert a red/black tree type whiteboard problem) because he wasn't a good programmer or because the mental model was so different to what he was used to, and he really seemed to struggle with C#. I didn't give him a job because I thought the risk of having to let him go during probation was too high, which would have sucked given that he'd have been leaving a steady job to join us. Contrast this with another interviewee who was a nurse, and a self-taught programmer, who really did seem to get it. He nailed our assessments, and we made him an offer. He joined us and has worked out really well. It's not that I'm against hiring people with mismatched skills, or from an unusual professional background - far from it - but I need to see some glimmer of a good match during the selection process, particularly if somebody would be leaving stable employment to join us (not that we're unstable, but there's the probation period to successfully navigate) and/or - not really an issue now we're all WFH - they're planning to relocate to work with us.