Keyword advice tends toward two useless extremes: stuff your resume with terms until the robot is satisfied, or ignore keywords entirely because "good writing speaks for itself". Both misunderstand what the words are for.
Why the words matter at all
A recruiter with two hundred applications does not read two hundred resumes. They search the database for the two or three things that decide the role, and read what comes back.
That search matches words, not meanings. "Worked closely with senior leadership" is an excellent description of stakeholder management that will not be found by anyone searching for stakeholder management. You were not judged and rejected. You were not in the result set.
This is the entire mechanism. Not a robot scoring you, a search box, and whether your vocabulary matches the one being searched for.
Finding the right terms
They are in the job description, and their importance is signalled by repetition. Postings are written quickly, often by pasting from a previous version, and the things that genuinely matter surface repeatedly, once in the summary, again in responsibilities, again in requirements. The nice-to-haves appear once, in a list at the bottom.
So count. A term mentioned four times is worth restructuring a bullet point around. A term mentioned once probably is not worth touching your resume for. The keyword matcher does this counting and shows you which of the weighted terms your resume is missing.
Where to put them
Inside the sentence describing what you did with them. Not in a list. This is the whole technique.
Weak: Skills: SQL, Python, Tableau, stakeholder management, forecasting
Strong: Built the weekly revenue forecast in SQL and Python, and presented it to commercial directors, the stakeholder management that turned it into three pricing changes.
The second contains the same terms, matches the same searches, and tells a person something. The first tells them only that you can list nouns. Increasingly it also scores worse, because several systems weight terms by whether they appear in context rather than in a block.
The keyword-stuffing tell
Recruiters spot a padded resume immediately, and the tells are consistent: a skills section far longer than the experience section; the same phrase repeated verbatim in three bullet points; terms in the skills list that appear nowhere in the work history; a suspiciously exact echo of the job advert's phrasing.
The cost is not merely a failed application. It marks you as someone gaming the process, which is a bad first impression to give the person deciding whether to interview you.
White text and other tricks
Do not. Hiding keywords in white text or one-point type is old and well known. Parsers read the text layer, not the rendering, so it is plainly visible to the system, and to anyone who copies your resume into a text editor, which recruiters do.
Getting caught reads as dishonesty rather than resourcefulness, and companies do add people to permanent do-not-hire lists over it.
Tailoring at a sensible cost
Rewriting your resume for every application is unsustainable, and unnecessary. A workable approach:
Keep one strong base resume. Well written, parseable, honest.
Change the vocabulary, not the content. If they say "data engineering" and you wrote "built data pipelines", use their phrase for the same work. Ten minutes, not two hours.
Reorder the top third. Whatever is most relevant to this role goes first. Recruiters read from the top and stop early.
Rewrite the summary. Three lines, aimed at this role. Highest return per minute spent on the whole document.
What no amount of vocabulary fixes
If your resume does not parse, none of this happens. A two-column layout scrambles your text before any search runs against it, and a resume exported as an image contains no text to search at all.
So the order matters: run the ATS checker and clear the blockers first, then tune vocabulary against the specific posting. Doing it the other way round means carefully choosing words that never reach the database.