A little background: I have 10+ years of professional experience. Polyglot. Experience with extremely small to medium sized companies.
I re-used my previous resume, which did decently well around 2019 when I was looking for a new position, but with updated info for the newest position I had. Applied to a number positions that I was very qualified for -- crickets. This put me in a bad spot mentally, honestly, as it felt like signals that I'm just not "good enough" for fancy "big tech".
I then updated my resume layout to be more parseable (admittedly this is another variable), then signed up for a service that helps ATS-ify my resume. This involved adding numbers to certain line items, reduce repetition, honestly some good feedback in general. Immediate recruiter messages the next day.
I was extremely averse to using a service like this as it just felt "dirty" or was a sign of my personal ethics "giving in" to some sort of system. Honestly, I still kind of feel that way, but this is the game we play now. I know for a fact I've been auto-rejected from a number of roles that I was 100%+ qualified for because of my resume.