I don't know if this is a startup or valley or techbro thing but in my industry there is no ageism that I can detect.
In aerospace they seem to prefer people who know where the bodies are buried, know how to bury bodies, have buried a few bodies themselves, and can instruct others on body burying.
In aerospace they seem to prefer people who know where the bodies are buried, know how to bury bodies, have buried a few bodies themselves, and can instruct others on body burying.