Seems like the author is a bit frustrated from unrealistic expectations. Hits home as we’ve not filled a role for over six months.
Sounds like a you problem, TBH. To be even more honest if, after six months, you haven't yet realised what the problem is, your company has deep self-awareness issues.
It's quite simple: if the candidate you want is not applying for your open position, then that's on you; increase the comp, the benefits, the work environment, anything, until the candidate you want sends you a CV.
You're bidding on an open market for talent. I find it hard to believe that the talent you want does not exist.
And you haven't had a single candidate that could possibly pick up the missing skills[1]?
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[1] I don't know what those are. There are two extremes here:
1. PhD level Maths is involved.
2. You require them to have experience in a specific product (anything from a Python library to a framework like HF)
If your requirements are closer to the first extreme, well sure, you're gonna have to wait for someone that has that.
If your requirements are closer to the second extreme, why not just take a candidate? If it takes 2 months to skill up on whatever product you need them to skill up on, right now you would have had that position filled for the last 4 months with your ideal candidate.