The actual technologies matter less, and I'm not talking about "the fundamentals". It's more that they tend to have only been doing the exact small set of thing

The actual technologies matter less, and I'm not talking about "the fundamentals". It's more that they tend to have only been doing the exact small set of things for a long period of time. When I've hired such people much more often than not they struggle to learn, because they're no longer used to learning. And much like I said the prior as a fellow greybeard, I'm saying this as someone who is much more cavalier than most people I've met about not expecting an exact set of skills. That said, I've noticed patterns of candidates who really struggle to catch up on their missing skills and this is one of them. EDIT: to clarify a bit, the archetype I'm talking about are people who have pretty much turned off their brain and been on autopilot for 10, 20, or more years. It's not a problem if they're using a "dated" technology or whatever, it's a problem that they've been operating on rote muscle memory for ages. There are absolutely people who are using the dated technologies who don't fall into this trap.