This doesn’t match my experience at all. A lot of companies at the cutting edge know that nobody is ramped up on their area and aren’t trying to limit themselve

This doesn’t match my experience at all. A lot of companies at the cutting edge know that nobody is ramped up on their area and aren’t trying to limit themselves to only poaching from competitors. In particular at big tech your previous scope and projects (like launching features, leading a feature or infrastructure team, shipping an entire product) are so much more important than eg your background in advertising - a background in advertising may be a plus for an advertising team, especially if you’re getting hired at a very high level (8+), but not a requirement or even target for recruiting purposes. I know HN loves to hate on big tech but a lot of the cutting edge is there. IME startups and “less selective” companies are more focused on getting people with very specific experience because they can’t afford to train someone up or risk them being a bad fit - and while startups almost by definition are doing something different than incumbents, that doesn’t mean they’re the whole cutting edge. Or, they are old-school and bin everyone as a “Java spring boot dev” either because HR doesn’t understand what things are easy to learn and what are hard, or engineering buckets themselves into these fixed categories and has a kind of “my turf”/static mindset with no expectation to learn or work on new things.