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ATS & Keywords

What Is ATS and How Does It Work? Everything Job Seekers Need to Know

6 min read

The Gatekeeper You Never Knew About

When you click "Apply" on a job listing, your resume doesn't land on a recruiter's desk. It lands in software. An Applicant Tracking System, ATS, is the first stop for virtually every application submitted to a mid-size or large company.

Over 98% of Fortune 500 companies use ATS software. But it's not just enterprise: startups, government agencies, and mid-market companies use them too. If you've applied for a job online in the last five years, your resume has been processed by an ATS.

What an ATS Actually Does

An ATS serves two main functions:

1. It Organizes Applications

Recruiters at popular companies receive hundreds, sometimes thousands, of applications per role. ATS software stores, categorizes, and sorts those applications so recruiters can manage the volume.

2. It Ranks and Filters Candidates

This is the part that matters to you. The ATS scans your resume, extracts structured data (name, contact info, work history, skills, education), and compares it against the job description. Based on keyword matches, formatting, and other signals, it assigns a relevance score.

Recruiters typically review only the top-ranked candidates. If your score is too low, your resume stays in the system, unseen.

How ATS Parses Your Resume

The parsing process works like this:

  1. File intake: The ATS accepts your uploaded file (PDF, DOCX, or plain text)
  2. Text extraction: It reads the text content from your document
  3. Field mapping: It tries to map your content into predefined fields, name, email, phone, job titles, company names, dates, skills
  4. Keyword analysis: It compares your resume's content against the job description's requirements
  5. Scoring: It generates a relevance score based on the match

Problems occur at every step. If your formatting is complex, step 2 fails. If your headers are non-standard, step 3 fails. If your keywords don't match, steps 4 and 5 work against you.

The Most Common ATS Systems

Different companies use different ATS platforms, but the major players include:

  • Workday, Common in enterprise and healthcare
  • Greenhouse, Popular with tech companies and startups
  • Lever, Used by growth-stage companies
  • Taleo (Oracle), Widespread in government and large enterprise
  • iCIMS, Used across industries in mid-to-large companies

Each system parses slightly differently, but the fundamentals are the same: clean formatting, standard headers, and keyword alignment.

What Gets Resumes Filtered Out

Poor Formatting

Graphics, icons, multi-column layouts, tables, and text boxes can all cause parsing failures. The ATS either misreads the content or skips it entirely.

Missing Keywords

If the job description asks for "Python" and your resume says "programming," the ATS may not make the connection. Exact and near-exact keyword matches drive your score.

Non-Standard Section Headers

Headers like "My Professional Story" or "Core Superpowers" confuse the parser. Stick with the basics: Experience, Education, Skills, Summary.

File Format Issues

While most ATS systems handle PDF and DOCX well, some older systems struggle with complex PDFs. When in doubt, submit a cleanly formatted DOCX.

How to Work With ATS, Not Against It

The goal isn't to "trick" the system. It's to present your genuine qualifications in a format the system can process accurately. Here's the approach:

  1. Use clean, single-column formatting with standard fonts
  2. Mirror the job description's keywords naturally throughout your resume
  3. Use standard section headers that ATS parsers expect
  4. Standardize your date formats and bullet characters
  5. Include a skills section with keyword-rich, discrete skill items
  6. Tailor your resume for each application

ATS Is Not the Enemy

ATS systems aren't designed to reject qualified candidates. They're designed to handle volume. The problem is that most resumes aren't formatted to be parsed correctly, so qualified people get filtered out by accident.

Understanding how ATS works gives you a real advantage. You're not competing against the system, you're working with it. And that puts you ahead of the 75% of applicants who never learned how.

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