What Is an Applicant Tracking System (ATS)? Everything Job Seekers Need to Know
An Applicant Tracking System (ATS) is recruitment software that manages the entire hiring workflow from job posting to offer letter. For job seekers, the ATS is the digital gatekeeper that determines whether your resume reaches a human recruiter. Understanding what ATS is and how it works is no longer optional—it's essential for modern job searching.
Definition and Purpose of ATS
An Applicant Tracking System is enterprise software designed to streamline the recruitment process. It automates the collection, storage, tracking, and screening of job applications, serving as the central hub for all hiring activities.
For employers, ATS solves a volume problem. A single job posting can generate hundreds to thousands of applications. Without ATS, recruiters would spend days manually reading resumes. The ATS automates initial screening, allowing recruiters to focus their time on the most qualified candidates.
For job seekers, the ATS represents both an opportunity and a challenge. If your resume is properly optimized, the ATS can quickly surface you as a top candidate. If not, your application may never be seen regardless of your qualifications.
Why Companies Use ATS
The primary driver for ATS adoption is efficiency. Companies receive an average of 250 applications per job posting, and large companies may receive thousands. Manually processing this volume is impractical and expensive.
Compliance is another major factor. ATS systems help companies maintain records required by employment law, including EEO (Equal Employment Opportunity) data, OFCCP compliance, and GDPR requirements for international companies. The ATS creates an audit trail of every application and hiring decision.
ATS also improves collaboration among hiring teams. Recruiters, hiring managers, and interviewers can all access candidate information, share notes, and track progress through a centralized system.
- Process high volumes of applications efficiently (250+ per posting)
- Maintain compliance with employment laws and regulations
- Standardize the hiring process across the organization
- Enable collaboration between recruiters and hiring managers
- Build a searchable database of candidates for future openings
Most Popular ATS Platforms
The ATS market includes dozens of platforms ranging from enterprise solutions to small-business tools. Knowing which ATS a company uses can help you tailor your application.
Workday dominates enterprise hiring, used by companies like Amazon, Netflix, and Bank of America. Greenhouse is popular with tech companies and startups. Lever combines ATS with CRM functionality and is used by companies like Shopify and Netflix. Taleo (Oracle) is common in large enterprises and government organizations. iCIMS is widely used in healthcare, finance, and retail.
Smaller companies often use platforms like BambooHR, JazzHR, Breezy HR, or Zoho Recruit. Each platform has different parsing capabilities and formatting requirements, but the core principles of ATS optimization apply across all of them.
| ATS Platform | Market Segment | Notable Users |
|---|---|---|
| Workday | Enterprise | Amazon, Netflix, Bank of America |
| Greenhouse | Tech/Startups | Airbnb, Slack, HubSpot |
| Lever | Mid-market | Shopify, KPMG |
| Taleo (Oracle) | Enterprise/Government | Government agencies, Banks |
| iCIMS | Enterprise | Healthcare, Finance, Retail |
| SmartRecruiters | Mid-market | Visa, LinkedIn |
How ATS Affects Your Job Search
The ATS fundamentally changes how you should approach job applications. The traditional advice of creating one polished resume and sending it everywhere no longer works. Each application should be tailored to match the specific job description because the ATS scores based on keyword alignment.
Your resume format matters more than its visual appeal. A beautifully designed resume with columns, graphics, and creative fonts may look impressive to a human but be completely unreadable by an ATS parser. Substance and structure must come before style.
The ATS also means that timing and volume matter less than quality. Sending 100 generic resumes will yield worse results than sending 20 tailored resumes that score highly with each company's ATS.
Pro Tips
Research which ATS a company uses (check their career page URL or use tools like BuiltWith) to understand platform-specific requirements
Always apply through the company's official career portal to ensure your resume enters the ATS system properly
Tailor your resume keywords to each specific job description rather than using a one-size-fits-all approach
Supplement your ATS application with networking—employee referrals often get flagged for priority review in the system
Keep your LinkedIn profile aligned with your resume, as some ATS platforms pull LinkedIn data for additional screening
Common Mistakes to Avoid
Applying through third-party job boards instead of the company's direct career portal, which can result in formatting loss
Using the same generic resume for every application without tailoring keywords
Assuming small companies don't use ATS—even companies with 50 employees increasingly use ATS tools
Ignoring the application form fields and only uploading a resume, missing required screening questions