The ATS myth
The most common advice when a resume is not getting responses is to optimize for ATS: add more keywords, reformat for parsing, mirror the job description language. This advice is not wrong exactly, but it addresses the wrong problem.
ATS systems parse and store resumes. They rarely reject them outright without a human involved. The more common failure mode is that a recruiter searches the system and your resume does not surface -- or it does surface and the human reading it stops within thirty seconds.
Keyword stuffing to game ATS often makes the document worse for the person who eventually reads it. That person is the more important audience.
The real reasons resumes do not get responses
Most resume problems fall into four categories. They are document integrity issues, not keyword issues.
Bullets that make claims without supporting them. "Results-driven leader with a track record of driving growth." "Strategic thinker with strong communication skills." These phrases add no information. A recruiter reads past them instantly because they describe what the candidate wants to be seen as, not what they actually did. Every claim needs a named example, a number, or a specific outcome.
Elements that reveal or allow inference of the candidate's age before they get a fair read: graduation years from decades ago, experience listed from the 1990s, outdated technology references, or a career history so long it requires three pages with no editorial organization. These trigger implicit bias. Removing them does not change your qualifications. It removes an unnecessary filter.
Most resume bullets describe what the person was supposed to do, not what happened as a result of them doing it. "Responsible for managing a team of twelve engineers" describes a job title, not an accomplishment. "Led a team of twelve engineers through a platform migration that reduced infrastructure costs by 30% and shipped two months ahead of schedule" describes an outcome. Outcomes get read. Responsibilities get skimmed.
A recruiter's first pass is fast. If they cannot find your current role, your company names, and your most recent accomplishments within ten seconds, they move on. Dense formatting, unusual structures, graphics-heavy layouts, and missing dates all slow down that first pass. The most readable resume is not the most creative one. It is the clearest one.
What to fix first
If you are going to prioritize, fix in this order.
First: remove abstraction. Go through every bullet and ask whether a stranger reading it would know exactly what you did and what resulted from it. If not, rewrite it or cut it. Vague bullets are worse than no bullets. They take up space and signal that there may not be substance behind the claim.
Second: check your age signals. If your resume includes a graduation year from the 1990s or earlier, remove it. If you have experience listed from more than fifteen years ago, consider whether it needs to be on the document at all. If it does, make sure it is organized in a way that makes the timeline easy to read, not a reason to estimate your age.
Third: rewrite responsibilities as outcomes. For each role, identify the two or three things you accomplished that you can name specifically. Replace responsibility descriptions with those. If you genuinely cannot name a specific outcome from a role, the bullet probably should not exist.