ATS-Friendly Resumes for Tech: Checklist & Red Flags

ATS-friendly resumes for tech aren't written for a robot - they're written so the robot doesn't break them on the way to a recruiter. Almost every tech company, from a 30-person startup to an enterprise, takes applications through a system like Greenhouse, Comeet, Workday or Lever. The system splits your file into fields, stores it, and the recruiter searches it. If the parsing fails or the right terms are missing, you simply don't show up.

This guide covers what these systems actually do, the seven red flags that show up most in tech resumes, and a ten-point checklist you can run before every application.

What is an ATS, and how does it read your resume?

An applicant tracking system collects applications, extracts your name, contact details, roles, dates, education and skills, and stores them as a record recruiters can filter and search.

The critical step is parsing. The system reads the file top to bottom and tries to work out which text belongs to which section. A simple layout - heading, role, dates, bullets - parses reliably. Two columns, tables or text boxes can make the system mix lines from different columns, attach a date to the wrong role, or skip text altogether.

Then comes search. A recruiter opens a role, gets dozens or hundreds of applicants, and filters: by keyword (React, Kubernetes, Product Manager), by the screening questions you answered, and sometimes by a match score the system computes. If your terms aren't in the file, you don't come up - even with the right experience.

Does an ATS automatically reject resumes?

Mostly no. In most systems a person makes the rejection call. What actually happens is that resumes that parsed badly, or that lack the terms a recruiter searches for, sink to the bottom of the list where nobody reaches them.

Automatic rejection does happen in two cases: knockout questions on the form ("Do you have 3+ years of Python?" - answer no, you're out) and rules the company sets in advance, such as location or work authorization. The widely shared figure that "75% of resumes are rejected by a machine" doesn't trace back to research anyone can check - don't build on it, but don't dismiss the problem either: a file that isn't read correctly is a file that isn't found.

Which mistakes get tech resumes lost in screening?

These seven come up again and again in resumes from developers, product managers, QA and data people. Most are formatting, and each takes minutes to fix.

1. Columns, tables and text boxes

A two-column template that looks great can be read as one long line that merges your skills column into your experience. Tables and floating text boxes are sometimes read out of order, sometimes not at all. The fix: one column, with skills as a plain list in their own section.

2. Contact details in the header or footer

Some systems ignore the header and footer areas of a Word document. If your phone and email live only there, your record may be saved with no way to reach you. Put contact details in the body, under your name.

3. Creative section headings

"My Journey" or "What I've Built" doesn't tell the system this is your experience section. Use headings every system recognizes: Experience, Education, Skills, Languages - plus Military Service if it's relevant.

4. Keywords with no context

A line at the bottom listing twenty technologies may help you surface in search, but a recruiter reading it sees there's nothing behind it. Every important tool should also appear inside an achievement: "Built a payments service in Node.js and PostgreSQL processing 50K transactions a day."

5. Responsibilities instead of achievements

"Responsible for server maintenance" describes a job, not you. "Cut deployment time from 40 minutes to 6 with GitHub Actions" describes a result. The system may not care about the difference; the recruiter who opens the file next does.

6. A file that's really an image

A scanned PDF, or an export from a design tool that flattens the page into an image, looks fine but contains no text. Quick test: open the PDF, select some text and copy it. If you can't select it, the system can't read it.

7. Job titles and abbreviations that don't match the ad

If the ad asks for a Backend Engineer and you wrote "Server-Side Developer," or you only wrote K8s while the recruiter searches for Kubernetes, you may not come up. Use the ad's wording, and spell out abbreviations the first time: Kubernetes (K8s).

One column or two: which is safer for ATS?

One column parses most reliably. Two columns can work in modern systems, but the risk of a garbled parse is higher - and for a role you care about, it isn't worth the gamble.

• Parsing: one column is read in the right order almost every time; two columns depend on the system, and lines sometimes merge.
• Space: one column is slightly less dense; two columns fit more on a page.
• Human reading: both work when the design is clean; two columns make the eye jump more.
• When to choose: one column almost always, and certainly when applying through a company's careers site; two columns when you're sending it straight to a person by email or LinkedIn.

Checklist: 10 things to verify before you apply

• Single column, with no tables, text boxes, icons or skill-level bar charts.
• Contact details in the body, not the header or footer.
• Standard headings: Experience, Education, Skills, Languages.
• Reverse-chronological order, with month and year for every role.
• The job title and core technologies from the ad appear in your resume with the same wording.
• Every experience bullet starts with a verb and ends with an outcome, ideally a number.
• A standard font (Arial, Calibri, Helvetica) at 10-12 pt, with no pale text colors.
• One page up to about five years of experience, two at most after that.
• A PDF with selectable text - or Word if the ad asks for it.
• A clean file name: Full-Name-Role.pdf, not "resume final v3."

How do you add keywords from the job ad without stuffing?

Take the 5-8 terms the ad repeats or emphasizes, and give each a natural place: your summary, an achievement bullet, or your skills list. A term that appears only in a list is weak; one that also appears in an achievement is strong.

• Mark the requirements that appear more than once - those are what the recruiter will search for.
• For each term, check where it already appears in your resume. Experience you have but didn't write down is the cheapest gap to close.
• Use the ad's exact wording. If it says "Product Manager," don't only write "PM."
• Don't add a tool you haven't used. The technical interview will ask about it.

For a deeper look at how scoring and keyword matching work, read our ATS optimization guide. If your military service is a core part of your experience, see how to translate military experience into a tech resume.

PDF or Word: which file type is better for ATS?

A PDF with real text is the right default: the layout holds and every modern system reads it. Send Word only when the ad asks for it, or when a recruiter wants to edit the file.

If you write in a right-to-left language such as Hebrew, there's an extra reason to prefer PDF: Word can open the file with broken text direction, especially around English terms. A PDF locks the direction as you saw it.

How can you test whether your resume is ATS-friendly?

The fastest test needs no tool at all: copy everything from your PDF and paste it into a plain text file. If the order survives - name, details, role, dates, bullets - a system will read it correctly too.

• Lines from different columns mixed together? Switch to one column.
• Missing text, such as your contact details? It's in a header or a text box.
• Garbled characters or question marks? A font or export problem - re-export with a standard font.
• Nothing pasted at all? The file is an image and needs to be exported again as text.

If you'd rather not fight a Word template, Custro's resume builder uses single-column templates with standard headings, and its PDF export keeps real, selectable text - the free plan covers one resume. If you apply to many roles, Pro tailors the content to each job ad and shows which terms are missing. For a full two-week plan from resume to interviews, see the accelerated tech job search guide.