I use LibreOffice has my word processor, and no substantial amounts of automation to speak of. And each time I intend to submit a resume, I save off a new copy and tailor it specifically for the recipient employer. After all, what's relevant and worth highlighting (not literally!) to one employer won't be the same as for another.

Yes, I'm aware that a lot of recruiters/reviewers use LLMs as a first-pass filter, but that's precisely why my submission should be crafted by hand each time: if it's an LLM, then I want its checkbox exercises to be easily met, and if it's a human, I want to put my best foot forward.

In days of yore, where paper resumes were circulated by hand to prospective employers at career fairs, having a bespoke resume for each would have been difficult to pull off. But with PDF submissions, there's no reason not to gear your submission to exactly the skills that a company is looking for.

To be clear, tailoring a resume does not mean adding fake or hallucinated qualifications that you do not possess. Rather, it means that you copyedit the resume so that your relevant skills are readily apparent. If you already listed an example project from a prior employer or internship, but a different project would better align to the prospective employer, consider swapping out the example for max appeal. Bullet-points are particularly easy to rearrange: if you have web-dev skills and that's desirable by the employer, those should be moved up the list of bullet-points. And so on.

Although resumes are now mostly PDFs, the custom remains -- both as an informal fairness criteria between applicants, but also because it would be more to read -- that one's resume should fit on a single sheet of US Letter or A4 paper, barring unique exceptions like professors that have long lists of published papers or systems architects that hold patent numbers. And so the optimization problem is how to most effectively use the space on that sheet of digital paper.