elwes3

Uh then there is 0 difference between an older dev and younger dev (by your own definition other than age). An older dev that 'knows all the new tech' may not have the concentration you need. You can not tell me as a hiring manager if you see someone changing jobs every other year you think it odd? I know I do when I see resumes like that. If they have the right skills I ask them to explain it.

You are just justifying being ageist. You mental gymnastics to do so are in your second to last line.

Exp in older stacks, that are 'obsolete' in your eyes, has helped me so many times with newer stacks. They usually make the same mistakes/patterns and have the same bits connecting it together at the OS level. A more experienced dev from another stack may say 'hey if this stack had XYZ from this other stack this would be so much easier' They then will get that thing done.

If you are skipping people because they do not know your particular stack you are missing out on a lot of people. The fresh young grad is not going to know any stack and will have no exp to draw upon when it goes sideways. That is why you pair them with someone who does have that exp to draw upon. Sometimes you want that crusty old ways too. Linux is a hodge podge of tech smashed together drawing from well over 40 years of tech stacks. Each with its own quirks.