What Do ATS Systems Actually Look For?

There is a persistent myth that ATS systems are mysterious black boxes designed to reject you. They are not. Applicant Tracking Systems are database software built to help recruiters organize, search, and filter candidates. They were not created to eliminate qualified people -- they were created because recruiters at mid-size and large companies receive hundreds or thousands of applications per role and need a way to manage the volume. Understanding how ATS systems work -- and how the major platforms differ from each other -- gives you a concrete advantage over candidates who treat the whole process as an unknowable force.

This guide breaks down the five most widely used ATS platforms, explains how they parse resumes, explores the difference between keyword and semantic matching, and covers the most common reasons qualified candidates get filtered out. For a complete optimization walkthrough with step-by-step formatting instructions, see our complete ATS optimization guide (/guides/complete-ats-optimization-guide).

How ATS Parsing Actually Works

When you upload or email your resume, the ATS runs it through a parser -- software that converts your document into structured data fields. The parser attempts to extract your name, contact information, work experience (company names, titles, dates), education (institution, degree, dates), and skills into a candidate profile. Recruiters then search and filter these profiles by keywords, years of experience, education level, location, and other criteria they define for each open role.

The critical thing to understand is that the parser is not "reading" your resume the way a human does. It is looking for patterns: section headers it recognizes, date formats it can extract, company names it can identify, job titles it can categorize, and keyword lists it can index. If your formatting confuses the parser, your information ends up in the wrong fields -- or gets lost entirely. A beautifully designed resume with a two-column layout, custom fonts, and artistic icons can be completely illegible to an ATS parser.

• Section headers must be standard and recognizable: "Experience," "Work Experience," "Education," "Skills" -- not "Where I Have Made an Impact," "My Journey," or "What I Bring to the Table."

• Date formats should be consistent throughout: "Jan 2022 - Present" or "01/2022 - Present." Do not mix formats like "January 2022" in one entry and "2022-01" in another.

• File format matters more than most people realize: PDF and DOCX are universally supported. Avoid image-based PDFs (scans), .pages files, .odt files, or any format that embeds text as a graphic.

• Tables and columns can break parsing: Many ATS parsers read content left-to-right, top-to-bottom in a single stream. A two-column layout can scramble the order of your content, mixing experience bullets with education details.

Think of the parser as a very literal reader. It does not infer or interpret. If your job title is in a sidebar and your company name is in the main column, the parser may not connect them. If your skills are listed inside a graphic element, the parser may not see them at all. The goal is to make your resume as easy to parse as possible, which usually means simple, single-column formatting with standard section labels.

The Big Five: How Each ATS Differs

Not all ATS platforms parse resumes the same way. Each has its own strengths and quirks, and the system a company uses can affect how your resume gets processed. Here is what you should know about the five most common systems you will encounter during a job search.

Greenhouse

Used by many tech companies and high-growth startups, including companies like Airbnb, HubSpot, and Cloudflare. Greenhouse has a relatively modern parser that handles most standard resume formats well. It supports PDF and DOCX, and its parsing is generally accurate for single-column layouts with standard headers. Greenhouse also allows recruiters to add custom screening questions to the application form, so pay attention to those -- your resume alone may not be the only filter. One distinctive feature: Greenhouse creates a structured candidate profile that recruiters can search across all open roles, so a well-parsed resume can surface you for positions you did not even apply to.

Lever

Common at mid-size tech and SaaS companies. Lever combines ATS and CRM functionality in a single platform, which means recruiters can source you from your parsed resume even if you did not apply to a specific role. Lever's parser works well with clean formatting but can struggle with creative layouts, headers placed in sidebars, and multi-column designs. Lever also indexes the text of your cover letter and any attachments, so keywords in those documents count toward searchability.

Workday

Widely used by Fortune 500 companies and large enterprises. Workday is one of the more rigid systems in terms of what it expects. It often asks you to manually fill in fields even after uploading a resume, because its parser frequently misfires on non-standard formats. If you are applying to a Workday-powered portal, keep your formatting extremely clean and expect to review the parsed output field by field before submitting. Many candidates lose information in the Workday parsing step simply because they do not check how their resume was interpreted.

iCIMS

Popular in healthcare, retail, hospitality, and large enterprises. iCIMS has been around for a long time and its parser is capable but conservative. It handles standard section headers and reverse-chronological formats well. Where it struggles is with functional or hybrid resume formats that do not follow a clear reverse-chronological work history. If you are applying to companies that use iCIMS, a traditional chronological format is your safest bet.

Taleo (Oracle)

One of the oldest and most widely deployed ATS platforms, common in government agencies, manufacturing, and legacy enterprise companies. Taleo's parser is the least forgiving of the five. It often requires candidates to copy-paste resume sections into separate text fields rather than relying on file upload parsing. If you encounter a Taleo application, prioritize the text fields over the file upload -- what you type into the form fields is what the recruiter will actually search and see. Many candidates upload a beautifully formatted resume to Taleo and then skip the text fields, not realizing that the upload is secondary to the structured data.

Keyword Matching vs. Semantic Matching

Older ATS platforms (and many current ones in their default configuration) use exact keyword matching. If the recruiter searches for "project management" and your resume says "program management," you may not show up in the results. This is why mirroring the exact language from the job description matters so much -- it is not about gaming the system, it is about speaking the same vocabulary the recruiter is using to search.

Newer ATS platforms and AI-powered add-ons are beginning to use semantic matching, which understands that "project management" and "program management" are related concepts. Some newer systems can also match skills to related competencies -- for example, understanding that "React" implies "JavaScript" and "frontend development." However, you should not rely on semantic matching being enabled at any given company. The safest strategy is still to use the exact terms from the job description wherever they accurately describe your experience.

A practical approach is to include both the specific term and the broader category when possible. "Led project management for 4 concurrent product initiatives using Agile methodology" covers "project management," "Agile," and "product" in a single natural-sounding bullet. You are not keyword-stuffing -- you are writing a complete sentence that happens to include the terms a recruiter is likely to search for.

Common False Fails (And How to Avoid Them)

A "false fail" is when a qualified candidate gets filtered out by the ATS for a formatting or structural reason rather than a lack of qualifications. These are frustratingly common and almost always preventable. Here are the ones we see most often.

• Graphics and icons in headers: Logos, skill bars, icons, and decorative elements are invisible to parsers. If your contact information is inside a graphic header, the ATS may not extract your email address or phone number at all.

• Text in document headers and footers: Many parsers skip the header and footer regions of a DOCX or PDF. Put your name and contact information in the main body of the document, not in the page header.

• Unusual file formats: .pages, .odt, and image-based PDFs (scanned documents) are frequently unreadable by ATS parsers. Stick to native DOCX or text-based PDF generated from a word processor.

• Acronyms without spelled-out versions: Write "Search Engine Optimization (SEO)" the first time so both the full phrase and the acronym get indexed. A recruiter searching for "SEO" will find you, and one searching for "Search Engine Optimization" will too.

• Non-standard job titles: If your actual title was "Client Happiness Lead" but the role you are applying for says "Customer Success Manager," add a parenthetical: "Client Happiness Lead (Customer Success Manager)." This preserves honesty while ensuring the ATS can match your title to the role.

• Missing section headers: If you use a creative layout that omits standard headers like "Experience" or "Education," the parser may not know how to categorize your content. Always include explicit section labels.

How to Test Your Resume Against an ATS

The best way to know if your resume will parse correctly is to test it before you apply. Vivid Resume's free scanner (/resume-score) runs your resume through a parsing analysis and shows you exactly how your sections, keywords, and formatting score against a target job description. It takes less than 30 seconds and reveals problems you can fix before they cost you an interview.

You can also do a manual test: upload your resume to a few job application portals and review how the parsed fields look before clicking submit. If your work experience ended up in the education field, or your skills are missing entirely, or your most recent job title got merged with a previous employer, your formatting needs work. Workday in particular shows you the parsed output and lets you correct it -- take advantage of that review step every time.

Another useful test: copy-paste your resume into a plain text editor like Notepad. If the content reads in the correct order and all your information is present, the resume is likely parser-friendly. If the text is jumbled, columns are interleaved, or sections are out of order, you have a formatting issue that an ATS parser will struggle with too.

ATS software is not your enemy. It is a filter that rewards clear formatting, relevant keywords, and standard structure. The candidates who understand the system -- and format their resumes accordingly -- consistently outperform equally qualified candidates who do not. That advantage compounds with every application you send.