The Complete Guide to ATS Systems in 2026

ATS systems attract more myths than almost any other part of job hunting: "the robot rejects 75% of applicants", "hide keywords in white text", "without a score of 100 you have no chance". To see what really happens, it helps to look at the system from the side of the people who use it every day: the recruiter and the hiring manager.

This guide explains how an ATS works from the hiring team's side, and what that means for how you apply. The resume side - structure, formatting and red flags - is covered in ATS-friendly resumes: checklist and red flags.

What happens to your resume after you click "Apply"?

The file enters the system, is parsed into fields, and is attached to the job as a candidate record. It then waits in the queue until a recruiter opens the role, searches or filters - only then does a person read it.

• Intake: the application arrives from the careers page, a job board, LinkedIn or an employee referral. Most systems record which channel each candidate came from.
• Parsing: the system extracts name, contact details, roles, dates, education and skills into separate fields. Anything that doesn't parse cleanly won't show up in search.
• Screening questions: answers to questions like "Are you authorized to work here?" or "How many years of Python?" are stored and used as filters.
• Pipeline: the candidate enters the first stage of the hiring pipeline, usually "New" or "To review".
• Human review: a recruiter scans the list, searches, filters, and moves candidates forward.

How do recruiters search and filter candidates?

Mostly through keyword search and filters: title, seniority, location, skills and screening answers. A candidate whose resume lacks the right words simply doesn't come up.

When a role gets hundreds of applicants, a recruiter doesn't read them in order. She searches for the terms in the job ad - the job title, technologies, domain - and filters by what matters to the hiring manager. Many systems also let recruiters search the whole database, including people who applied to other roles in the past, so a resume you sent six months ago can still surface today.

The practical takeaway: the words the job ad uses should appear in your resume, in the ad's own phrasing. If the ad asks for "Customer Success" and your resume says "account management", you may not come up in search even though it's the same experience.

What are knockout questions, and why do they matter more than your resume?

Knockout questions are screening questions on the application form where a particular answer removes you from the queue. This - not the resume - is where most genuinely automatic rejection happens.

Common examples: work authorization, willingness to work in a given location, minimum years of experience, language skills. The company decides in advance which answers disqualify. Answer them carefully: a "no" to a question you could have answered "yes" with context is the fastest way to disappear from a process. Don't answer falsely to get through - it surfaces in the interview - but don't undersell the experience you have either.

Does an ATS rank candidates with a match score?

Some systems show a match score or ranking between the resume and the job ad, and more of them now use AI to do it. The score helps the recruiter prioritize; it doesn't decide for her.

How such a score is calculated varies by system, and most vendors don't publish it. What you can say is that it depends on what the system managed to parse from your file and on how well the content matches the ad. So the two things that improve it are the same two things that improve search: a file that parses cleanly, and content tailored to the specific role. Sites promising an "ATS score of 100" are measuring their own guess, not the system at the company you're applying to.

Which ATS systems do companies use?

In Israeli tech you'll commonly meet Comeet, Greenhouse, Lever, Workday and SmartRecruiters; smaller companies may use an HR system's recruiting module or simply an inbox. The principles are the same in all of them.

Each system has a different interface and feature set, but from your side the differences are small. They all ingest a file, parse it, support search and filtering, and move candidates between stages. A simple way to tell which one a company uses is to look at the application form's URL, which usually contains the vendor's name. That doesn't change how you write your resume, but it's a reminder that the form is part of the system and every field in it is stored and searchable.

Which ATS myths are true, and which aren't?

Most myths overstate the machine's role and understate the human's. Here are the five most common, with the short answer to each.

• "The ATS automatically rejects most resumes": the figures that circulate online don't trace back to research you can check. In most systems resumes aren't rejected by the machine; they sink to the bottom of search or are filtered out by screening questions.
• "Hide keywords in white text": hidden text shows up the moment someone copies or prints the file, and makes a bad impression. Keywords belong in the honest description of your experience.
• "PDFs can't be read by an ATS": a PDF with real text (not a scan) parses well in most systems. The problem is a PDF saved as an image.
• "You need a high match score to get an interview": the score is a prioritization aid. An employee referral, for example, moves a candidate to the top regardless of score.
• "Just send more applications": volume without tailoring creates records nobody finds. Fewer, tailored applications work better.

What does this mean for how you should apply?

Three things move the needle: an employee referral, a resume tailored to the ad, and applying early. They all work the same way - getting you in front of a human sooner.

• Referrals: in most systems a referred candidate is flagged separately and reviewed with priority. If you know someone at the company, ask for a referral before applying through the form.
• Tailoring: keep a version of your resume for each type of role, using the ad's terms. Custro's resume builder is free to start, and its Pro plan can tailor the content to each job ad automatically.
• Timing: many recruiters review the first applicants while a role is fresh. Applying in the first days after a posting beats applying three weeks later.
• A complete form: fill in every field, even if it repeats your resume. An empty field is one nobody can filter on.
• A direct message: a short note to the recruiter or hiring manager on LinkedIn turns you from a record in a queue into a name someone recognizes. The recruiter message templates give you wording that works.

And once a person does open your file, the interview is next - the tech job search plan shows how to get your resume, LinkedIn and interview prep ready in two weeks.