This is a check, not a rewrite
There are two different jobs people call “matching your CV to the job description”. One is editing a CV so it answers a specific posting well. The other is working out, before any editing happens, whether this posting deserves that effort at all.
This is the second one. Doing it first is what stops you spending an evening tailoring for a role with an eligibility gap you would have seen in four minutes. Once a posting passes the check, tailoring without rewriting everything covers the editing.
Step one: pull out what the posting actually asks
Write down the accountabilities — what this person owns — and the checkable specifics: named tools, domains, languages, qualifications, location or right-to-work conditions. Leave out anything a stranger could not verify from a CV. How to read a job description is the method for that split.
You want a short list. If it runs past about eight lines you are still carrying boilerplate.
Step two: put a piece of evidence against each line
Go down your list and, for each item, name the specific thing on your CV that demonstrates it: a project, a role, an outcome, a qualification. Not a feeling of competence — a line somebody else could read.
Each line ends up in one of three states.
- Evidenced. Something already in writing demonstrates it, and you could point at the sentence.
- Adjacent. You have done something close enough that a reasonable reader would accept the transfer — the same work in a different tool, or the same responsibility at a different scale.
- Absent. Nothing in your history speaks to it, or it is something you either hold or do not.
The distinction between adjacent and absent is where the decision lives. Adjacent gaps are arguable in a cover letter. Absent ones, particularly the eligibility kind, are not.
Step three: read the pattern, not the count
Resist the urge to total it up. A proportion of lines ticked tells you almost nothing, because the lines are not equally important and the list length was set by whoever wrote the posting.
Look instead at where the gaps sit.
- Gaps only among the specifics, with the accountabilities evidenced: a good application. Lead with the accountabilities and address the specifics honestly.
- Gaps in the accountabilities themselves: this is a stretch, and it needs a genuine reason for the reader to take it seriously.
- A gap in anything binary — a licence, a language, a right to work: skip it, and skip it quickly.
What a keyword checker is doing instead
Tools that report how many of a posting's words appear in your CV are measuring something real but narrow: lexical overlap. It is a reasonable proxy for whether an automated screen will pass you through, and a poor proxy for whether you can do the job.
The practical consequence is that the same CV scores differently depending on the vocabulary a company happens to use, and that padding your CV with a posting's exact phrasing improves the reading without improving the application. Worth knowing what you are optimising — why a percentage is not a decision goes into it.
Keep the residue
Write down what was absent, in two or three words, each time you run this. Over a fortnight of applications the same one or two items keep appearing, and that is the most reliable careers advice you will get: it is specific to the roles you are actually chasing, it came from real postings, and it is usually learnable.