What Is an ATS Applicant Tracking System? Everything Job Seekers Should Know

What is an ATS applicant tracking system and why it exists

If you’ve ever applied for a job online and never heard back, chances are your resume didn’t even reach human eyes. The reason? An ATS applicant tracking system, the digital gatekeeper used by most employers today. An ATS is a software platform that automates the hiring process: it collects, sorts, and ranks job applications based on keywords, qualifications, and other criteria set by recruiters. Instead of manually reviewing hundreds or even thousands of resumes, companies use ATS software to instantly filter out candidates who don’t meet basic requirements. According to Forbes , up to 75% of resumes are rejected by ATS filters before a recruiter ever sees them. And a SHRM report found that 79% of recruiters use AI-powered tools, including ATS, to speed up hiring decisions and reduce screening time. What started as a tool for Fortune 500 companies has now become a standard across businesses of all sizes. Whether you’re applying to a tech startup, a marketing agency, or a university, your resume will likely pass through an ATS first.

How an ATS applicant tracking system works

To understand how to beat the system, you first need to understand how it works. Most ATS platforms follow a similar four-step process:

1. Resume parsing

When you upload your resume, the ATS scans it and extracts key information, name, contact details, skills, work experience, education, and more. If the formatting is too complex or the file type isn’t supported (for example, a graphic-heavy PDF), the ATS might fail to parse it correctly, causing you to be filtered out immediately.

2. Keyword matching

Next, the system compares your resume to the job description. It looks for keywords that match the required skills, qualifications, and responsibilities. If the role requires “project management” or “Python,” but those terms don’t appear in your resume, the system will rank you lower or reject your application altogether. Pro tip: Use the same phrasing from the job posting in your resume. If the company lists “social media strategy,” don’t just write “digital campaigns.” The closer the match, the higher your chances.

3. Scoring and ranking

The ATS then scores each resume based on how well it matches the job requirements. Recruiters often only review the top 10–20% of applications. That means even small improvements to keyword usage or structure can move your resume from the “reject” pile to the “review” pile.

4. Shortlisting for human review

Finally, the top-ranked candidates are sent to the recruiter or hiring manager. If you make it this far, your resume will finally be read by a real person, but the ATS filter is the first and most critical hurdle. Related reading:

• • How to Pass ATS Filters: Resume Optimization Guide

• • The Perfect Resume Doesn’t Exist — What to Do Instead

Why ATS systems matter for job seekers

The role of ATS applicant tracking system has grown beyond simple resume storage, today, they’re deeply integrated into the hiring process. For job seekers, this means two crucial things:

1. 1. You’re competing with algorithms before humans. Recruiters no longer have time to read every resume. In competitive industries, they rely on ATS scoring to narrow down the talent pool quickly.

1. 1. Your resume needs to be machine-readable and strategically written. Even a perfectly qualified candidate can be filtered out if the resume isn’t optimized for ATS parsing.

Here’s what that means in practice:

• • Formatting matters: Avoid tables, headers, or complex layouts. Stick to simple sections with clear headings like Experience, Education, Skills.

• • Keywords are crucial: If the job mentions “SEO strategy,” “Google Analytics,” and “content optimization,” include those exact terms naturally in your resume.

• • Relevance beats volume: Tailor your resume to each role. One-size-fits-all resumes often fail to score well.

A well-optimized resume can increase your chances of being seen by up to 80%.

The evolution of ATS: From simple sorting to AI-driven hiring

When ATS software first appeared in the 1990s, it was little more than a database tool, storing resumes and matching basic keywords. But the rise of artificial intelligence has completely transformed the landscape. Today’s systems go far beyond keyword matching. They can:

• • Analyze writing style and tone to assess communication skills.

• • Score candidates based on soft skills using NLP (natural language processing).

• • Integrate with LinkedIn to pull in extra context from your profile.

• • Predict candidate success using historical hiring data.

This shift is part of a larger trend: recruitment is becoming increasingly automated. According to SHRM, AI reduces time-to-hire by an average of 35%, and companies are investing heavily in tools that streamline candidate evaluation. For job seekers, this means you need to think strategically. It’s not just about writing a resume, it’s about training the ATS to see you as a strong candidate. Related reading:

• • The Ultimate Job Application Tracker: Stay Organized and Get More Interviews

• • The Fastest Way to Apply for Jobs Online

How to optimize your resume for an ATS applicant tracking system

If you take away just one lesson about ATS, it’s this: your resume must be written for two audiences, a machine first, and a human second. Even the most impressive career story won’t matter if the system can’t read or understand it. Below is a step-by-step guide on how to make sure your resume passes through ATS filters and lands in front of a recruiter.

1. Use the right file format and structure

Many resumes are filtered out not because of the content, but because of formatting errors. Applicant Tracking Systems are programmed to parse information from text-based files. If the file type or layout is unreadable, the system will reject it before it’s even reviewed. Best practices:

• • Save your resume as a .docx or .pdf (only if the job posting says PDFs are accepted).

• • Use a clean, single-column layout.

• • Avoid graphics, charts, tables, or text boxes, they confuse parsing algorithms.

• • Use standard section headers: “Experience,” “Education,” “Skills,” “Certifications.”

Related reading: The Perfect Resume Doesn’t Exist — What to Do Instead

2. Match keywords strategically to pass ATS filters

ATS algorithms rely heavily on keyword matching. They scan resumes for terms that reflect the skills, qualifications, and experience listed in the job description. If those words don’t appear in your resume, even if you have the skills, you won’t make the shortlist. How to do it:

• • Copy the job description into a keyword analysis tool (like a word cloud generator).

• • Identify the 10-15 most frequently used terms (e.g., “project management,” “CRM,” “Python,” “SEO”).

• • Naturally integrate these terms into your skills, experience, and summary sections.

• • Avoid “keyword stuffing.” ATS can detect unnatural repetition and may penalize it.

Pro tip: Use variations of keywords, for example, “project manager” and “project management”, to cover semantic differences. Related reading: How to Pass ATS Filters: Resume Optimization Guide

3. Use simple, clear language

ATS systems don’t understand creativity or metaphors. Phrases like “visionary growth ninja” or “data whisperer” might sound impressive to humans but will confuse the system. Instead, use industry-standard language that clearly communicates your skills and responsibilities. Instead of:

• • “Marketing Manager who revolutionized brand awareness.”

Try:

• • “Digital Marketing Manager who increased brand engagement by 65% through targeted social media campaigns.”

Clarity doesn’t just help the ATS, it also makes your resume more scannable for humans once it reaches the recruiter.

4. Add a skills section with core keywords

A dedicated Skills section is one of the most important elements of an ATS-optimized resume. It’s where the system looks first for key terms. Best practices:

• • List 8-12 skills that are directly relevant to the job.

• • Include both hard skills (e.g., JavaScript, project budgeting, SEO) and soft skills (e.g., communication, leadership, collaboration).

• • Mirror the language from the job posting wherever possible.

According to Forbes, resumes that closely match the job description are up to 70% more likely to pass initial ATS screening.

5. Focus on relevance and recency

The ATS often weighs recent and relevant experience more heavily than older achievements. A common mistake job seekers make is listing too much irrelevant information, which dilutes the impact of their resume. Tips:

• • Focus on the last 10-15 years of your career.

• • Emphasize accomplishments and metrics that align with the job description.

• • Cut or shorten older, unrelated roles unless they show transferable skills.

How to check if your resume will pass ATS filters

Once you’ve optimized your resume, the next step is to test it before submitting. This ensures your work won’t go to waste. Here’s how:

1. Use a free ATS scanner

Tools like Teal, Resumeworded, or Resume.io analyze your resume and show how well it matches a specific job posting. They break down keyword coverage, formatting issues, and section quality.

2. Compare to job description

Manually check whether you’ve included all major skills and terms from the posting. If the job description lists “CRM software” and “lead generation,” make sure those phrases appear naturally in your resume.

3. Run a plain text test

Copy and paste your resume into a plain text editor (like Notepad). If the structure breaks, or critical sections disappear, the ATS might not parse it correctly. Related reading: How to Pass ATS Filters: Resume Optimization Guide

7 Popular ATS systems you should know

Understanding the tools recruiters use can give you a huge advantage. Here are seven of the most widely used ATS applicant tracking systems and what each one does:

ATS Platform	What It Does
Workday	A comprehensive enterprise-level ATS that uses AI to screen resumes, parse candidate data, and provide analytics to help large organizations manage massive applicant volumes.
Greenhouse	Focuses on structured hiring workflows, collaborative decision-making, and interview scheduling, helping teams build consistent and fair recruitment processes.
Lever	Combines applicant tracking with candidate relationship management (CRM), enabling recruiters to nurture talent pipelines and maintain long-term engagement.
iCIMS	Offers highly scalable recruitment solutions, including automated screening, compliance tracking, and advanced reporting, ideal for large corporations.
SmartRecruiters	Uses AI to match candidates to roles, supports multilingual recruitment, and integrates with job boards and sourcing tools to attract global talent.
JazzHR	A simple, budget-friendly ATS designed for small businesses, offering job posting, resume management, and interview tracking without unnecessary complexity.
BambooHR	Combines ATS capabilities with a full HR management suite, allowing teams to manage hiring, onboarding, and employee data in one integrated platform.

Tip: If you know which ATS a company uses, you can tailor your resume for that system. For example, Workday prioritizes structured experience sections, while Greenhouse rewards resumes with well-defined skill sets and clear achievement statements.

Final Thoughts: ATS is a tool – not an obstacle

Many job seekers view the ATS applicant tracking system as a barrier,  but in reality, it’s a filter designed to help recruiters manage overwhelming applicant volumes. Your goal isn’t to “beat” the system but to speak its language. By following the strategies above from smart keyword use to clean formatting, you dramatically increase your chances of making it to the next stage: a real human review. Recommended next steps: The Ultimate Job Application Tracker: Stay Organized and Get More Interviews

FAQ: ATS applicant tracking system

1. How can I pass ATS filters?

To pass ATS filters, tailor your resume to the job description by including relevant keywords, skills, and job titles exactly as they appear. Use a clean, text-based format without graphics or tables so the system can parse your resume correctly. Always save it in .docx format unless the employer specifies PDF. Focus on clarity and relevance, even small changes in phrasing can significantly improve your ATS score.

2. How do I optimize my resume for an ATS?

Start by identifying the keywords in the job posting, skills, tools, certifications, and responsibilities and integrate them naturally throughout your resume. Add a dedicated Skills section with 8–12 relevant terms, and make sure they also appear in your work experience and summary. Use standard headings like Experience, Education, and Skills, and avoid complex formatting. Finally, run a quick “plain text test”, paste your resume into Notepad and ensure everything reads correctly.

3. How can I check if my resume will pass an ATS?

There are several ways to check. First, use a free ATS scanner like Teal, Resumeworded, or Resume.io to see how your resume matches a specific job description. Second, manually review the job posting and ensure you’ve included all major keywords and skills. Finally, submit your resume to a test application or a friend’s ATS system if possible, this gives you real feedback on how it’s parsed and scored.

4. What’s the difference between an ATS and a traditional resume review?

An ATS applicant tracking system is an automated filter that screens resumes based on specific criteria before they reach a human recruiter. Traditional review happens after the ATS shortlist. Recruiters typically only see 20–30% of resumes, the ones that pass the ATS screening. This means your first challenge isn’t impressing a person, it’s convincing the algorithm that you’re relevant.

5. How often should I tailor my resume for ATS?

Ideally, every time you apply. Even small adjustments, like changing “content writing” to “content creation” or “CRM platforms” to “Salesforce”, can increase your ATS score. If you’re applying to many similar roles, create a master resume template and customize keywords and phrasing for each job description.

6. Do cover letters matter for ATS?

Most ATS platforms don’t scan cover letters as deeply as resumes, but they still store and forward them to recruiters. A well-written cover letter can make a difference after you pass the initial screening, especially if it highlights keywords from the job description and explains how your experience aligns with the role.

7. Can I beat ATS with AI tools?

AI tools can help you tailor your resume more effectively by suggesting keywords, rewriting bullet points, and highlighting missing skills. However, they’re only effective if the information you provide is accurate. Think of AI as a helper, not a shortcut. The best results come from combining AI assistance with real customization.     Subscribe to the HirePilot newsletter to receive weekly job search tips, resume templates, and step-by-step AI strategies to stay ahead in a competitive hiring market.