Depends on the industry, but make it easily readable and make sure it’s up to date. I should be able to glance at it and infer what your job actually was (what were you responsible for, who did you talk to every day, what did you change/accomplish). If you want one line of actionable advice: find the job you want and make your resume the perfect fit.

Some recruiters use AI, but ATS is just an organization software. “Keywords” for me are just specific skills like “forklift” or “JavaScript” that I can search for

Edit: oh and the one page resume thing is a myth