There are four reliable ways to compile your keyword list, in roughly the order they pay off. First — and most important — reverse-engineer five real job postings for the role you're targeting. Copy the job descriptions into a single document and highlight every noun phrase, technology, certification, and verb that appears in three or more of the five. Those are your top-tier keywords. The ones that appear in two are second-tier, worth including if they fit your experience honestly.
Second, cross-reference the role on O*NET (the US Department of Labor's occupational database — onetonline.org). O*NET lists the standardised technologies, tools, knowledge areas, and skills the federal government tags each occupation with. ATS systems frequently use O*NET-derived synonym tables, so adding 2-3 O*NET-listed terms that aren't in the job description but match your experience can quietly boost your score.
Third, ask the recruiter directly when you have the chance. If a recruiter reaches out — even through LinkedIn — a polite "What are the must-have skills the hiring manager is screening on?" is appropriate and often answered. Their answer tells you what the system is configured to look for that's not necessarily in the public posting.
Fourth, run your draft through an ATS scanner. The scanner extracts your resume text the same way an ATS would, then compares it against a target job description and shows you the missing terms. Our free scanner is built into the editor — see the CTA at the end of this guide.