Applicant tracking systems scan for keywords, parse formatting, and read section structure. 75% of resumes get filtered out before a human recruiter sees them. Here's exactly what the algorithm is checking.
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The algorithm
When you submit a resume, it goes through an Applicant Tracking System before anyone sees it. These systems are designed to filter candidates—not find the best ones. Understanding what they look for is the difference between getting filtered out and getting the interview.
ATS scans your resume for exact and partial matches of keywords from the job description. If you don't have the right terms—even if you're qualified—you won't pass. Hard skills, software names, and specific certifications are weighted heaviest.
70% of ATS scoreThe ATS needs to extract your text from the file. .docx and .pdf parse most reliably. But if your resume uses tables, columns, text boxes, headers/footers, or embedded images—the parser loses content. Some reports say up to 25% of resumes lose critical information during parsing.
Often breaks silentlyATS expects standard section headers: "Work Experience," "Education," "Skills." It looks for patterns to categorize your data. If you use creative headers like "Where I've Made an Impact" or "My Professional Journey," the system may not recognize the section at all.
Standard headers work bestModern ATS doesn't just count keywords—it looks for numbers. "Managed a team" means less than "Managed a team of 12." "Improved processes" means less than "Reduced processing time by 34%." Quantified achievements get ranked higher.
Numbers = higher rankMost ATS systems read top-to-bottom and give more weight to earlier sections. Work experience typically matters most, followed by education and skills. If you put skills at the end, they may not be indexed for search. Content beyond page 2 is often not indexed at all.
Order mattersATS parses your job titles and compares them to the job title in the posting. "Senior Software Engineer" vs. "Lead Developer" might not match. The system is literal—it doesn't understand that these are similar levels.
Literal matching onlyWhy most resumes fail
Your resume might look perfect to a human reader. But ATS systems are not human. Here's what silently destroys your chances:
Two-column resumes with section dividers break most parsers. The ATS can't reliably reconstruct which text belongs where. Use a single-column layout.
Skill bars, achievement badges, or graphical elements get read as noise. Some parsers see them as formatting codes that corrupt the text extraction.
Text inside shapes, text boxes, or callout boxes often doesn't get parsed at all. Your most important achievements might be completely invisible to the ATS.
Don't name your file "John_Smith_Resume_Final_v2.pdf." ATS systems may see underscores or version numbers as extra characters. Use "john-smith-resume.pdf" instead.
Here's the worst part: when ATS rejects your resume, you never know. You get no notification, no feedback, no second chance. You just don't hear back—and assume the role went to someone else. Often, the role went to nobody qualified yet, but you'll never have the chance to apply again.
How it works
PlacedAI doesn't just check keywords—it simulates how major ATS systems (Workday, Lever, Greenhouse, Taleo) actually parse your resume. We identify exactly what's breaking your chances.
Paste your text or upload PDF/DOCX. We support all common formats used in job applications.
We simulate how the major ATS systems extract your content—and flag exactly what gets lost in parsing.
Get a complete breakdown of which keywords you're missing from the job description, and where to add them.
Not just the issues—get specific rewrites that fix them. Copy, apply, and resubmit with confidence.
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