What is an Applicant Tracking System?
An Applicant Tracking System (ATS) is a type of HR software that manages the hiring process from job posting to offer letter. For job seekers, the most important function is the initial resume screening: when you submit an application online, an ATS parses your resume, extracts key information (name, contact details, work history, education, skills), and scores or ranks it based on how well it matches the job requirements. Popular ATS platforms include Workday, Greenhouse, Lever, iCIMS, Taleo, BambooHR, and Jobvite.
How does ATS ranking work?
Most ATS systems use a combination of: (1) Keyword matching — the system compares words in your resume to the job description and counts matches. (2) Contextual parsing — newer systems use NLP to understand that 'led' and 'managed' are related, but explicit keywords still matter more. (3) Section recognition — the ATS looks for standard resume sections (Work Experience, Education, Skills) and may ignore content that appears outside expected structures. (4) Formatting parsing — tables, columns, headers, and images often break the parser, causing sections of your resume to disappear.
The most common ATS platforms and their quirks
Workday is the most widely used enterprise ATS. It requires very clean formatting and is sensitive to non-standard characters. Greenhouse is popular at tech companies and startups. It parses PDFs well but struggles with graphics. Lever is used by growth-stage tech companies. It has strong LinkedIn import but basic resume parsing. iCIMS is common in healthcare and enterprise settings. It strictly enforces section structure. Taleo (Oracle) is used by large corporations. It is one of the most aggressive ATS systems regarding formatting and keyword matching.
How to know if your resume passes ATS
The most reliable method is to use an ATS resume checker before applying. Upload your resume and paste the job description. The checker simulates how the ATS will parse your document and gives you a compatibility score. Launch CV's ATS Score Checker runs your resume against 15+ platform rules and returns a 0–100 score with specific issues: missing keywords, formatting problems, structure gaps, and date inconsistencies. The average unoptimized resume scores 45–60. After addressing the flagged issues, most users reach 80–90+.