ATS resume optimization: what actually gets you past the filter

What an ATS actually does

When you apply online, your resume is often stored in a database tied to the job requisition. The ATS extracts text from your file, maps it to fields (name, experience, skills), and may score how well you match the job description.

Recruiters then search and filter that database. If your file fails to parse—because of layout, images, or unusual fonts—your experience may appear incomplete even when you are qualified.

Formatting rules that protect parsing

Think simple structure first. These choices reduce parse errors across Workday, Greenhouse, Lever, and similar systems:

• Use a single-column layout for the main body.
• Stick to standard section headings: Summary, Experience, Education, Skills.
• Prefer common fonts (Arial, Calibri, Helvetica, Times).
• Avoid text in headers/footers for critical details (contact info belongs in the body).
• Skip graphics, skill bars, and icons that replace plain text.
• Use standard bullets (• or -), not custom symbols.

PDF vs Word: which to upload

Follow the employer’s instructions. When unspecified, PDF is usually fine if it is text-based (you can select/copy words). Scanned image PDFs parse poorly—export from a word processor instead.

Some older ATS versions parse .docx slightly better. If you suspect a parse issue, try docx when allowed and compare previews in the application portal.

Keywords without stuffing

ATS matching relies on overlap between your resume and the job description. Use the same phrases for tools and titles when truthful: if the posting says "customer success", mirror that instead of only "client relations".

Do not hide keywords in white text or footers—recruiters consider that deceptive, and modern systems may penalize it. Instead, weave terms into achievement bullets where you actually used those skills.

Section order and length

Put your strongest evidence early: summary and recent experience first. Skills can follow experience or sit after summary depending on your industry—tech roles often benefit from a concise skills block near the top.

Two pages are acceptable for experienced candidates if every line adds signal. One page is fine for early career. Avoid dense blocks; short bullets scan better for humans after ATS ranking.

How to test before you apply

Quick checks that catch most ATS issues:

• Copy all text from your PDF into a plain editor—if sections are missing or scrambled, fix the source file.
• Search your resume for 5 must-have terms from the posting; add them naturally where missing.
• Open the file on mobile—if it is hard to read, simplify layout.
• Ask a peer: can they identify your target role in 10 seconds?