Why You're Not Getting Callbacks — 7 Resume Mistakes That Fail ATS

Most job seekers blame the job market when they don't hear back. The real reason is usually simpler: their resume never reached a human.

In 2026, 75% of resumes are automatically rejected by ATS before any recruiter reads them. And the frustrating part — most of these rejections are caused by completely avoidable mistakes.

Here are the 7 most common ATS resume mistakes, and exactly how to fix each one.

Mistake 1 — Using a Fancy Resume Template

The problem

Multi-column layouts, icons, progress bars, graphics, profile photos — these look great in a PDF viewer. ATS sees them as broken, unreadable data.

ATS reads your resume like a text file. It scans left to right, top to bottom, in a single column. When it hits a two-column layout, it often reads both columns simultaneously — mixing your job titles with your skills, creating nonsense.

A resume that looks like this to a human:

Experience          Skills
Software Engineer   React, TypeScript
Google, 2022-2024   Node.js, PostgreSQL

Looks like this to ATS:

Experience Skills Software Engineer React, TypeScript Google, 2022-2024 Node.js, PostgreSQL

Unreadable. Rejected.

The fix

Use a single-column, text-based resume format. No tables, no text boxes, no columns, no icons, no photos. Plain fonts. Standard margins. It will look simpler — and it will actually get read.

Mistake 2 — A Generic Professional Summary

The problem

Most candidates write the same summary:

"Motivated professional with strong communication skills and a passion for delivering results in fast-paced environments."

This sentence contains zero keywords. ATS scores it near zero. And if it somehow passes ATS, a recruiter will skip it in 3 seconds.

The fix

Rewrite your summary for every application. Include:

• Your job title (matching the role you're applying for)
• Your years of experience
• 3-4 specific keywords from the job description
• One quantified achievement

Before:

"Experienced developer seeking new challenges."

After:

"Full-stack engineer with 4 years building scalable web apps using React.js, TypeScript, and Node.js. Delivered REST APIs in Agile sprints, improving system performance by 35%."

Use resume.codisim.com to automatically generate an ATS-optimized summary from your resume and the job description. Free, takes 10 seconds.

Mistake 3 — Wrong Keyword Phrasing

The problem

You have the skill. You just wrote it differently from the job description.

ATS is literal:

• "ReactJS" ≠ "React.js"
• "Postgres" ≠ "PostgreSQL"
• "JS" ≠ "JavaScript"
• "ML" ≠ "Machine Learning"
• "k8s" ≠ "Kubernetes"

If the job says "React.js" and your resume says "ReactJS" — many ATS systems won't match them.

The fix

Copy the exact phrasing from the job description. Before submitting, read the job description and check that every keyword appears in your resume in the same form it appears in the posting.

When in doubt — include both versions: "React.js (ReactJS)."

Mistake 4 — Missing or Weak Skills Section

The problem

Many candidates bury their skills inside experience bullet points and skip a dedicated Skills section entirely.

ATS specifically scans for a skills section. Keywords listed explicitly in a Skills section carry more weight than the same keywords buried in a paragraph.

Also — if your skills section exists but only lists 4-5 things, you're leaving ATS score on the table.

The fix

Create a dedicated Skills section near the top of your resume. List every relevant skill — technical tools, programming languages, methodologies, platforms.

Don't do this:

Skills: JavaScript, React, Node

Do this:

Technical Skills
Languages: JavaScript (ES6+), TypeScript, Python, SQL
Frameworks: React.js, Next.js, Node.js, Express.js
Databases: PostgreSQL, MongoDB, Redis
Tools: Docker, Git, GitHub Actions, AWS, Figma
Methodologies: Agile, Scrum, TDD, CI/CD

Mistake 5 — Saving the Wrong File Type

The problem

Some candidates submit DOCX when PDF is better. Others submit PDF with complex formatting that breaks on parsing. Some even submit JPG screenshots of their resume (this happens more than you'd think).

The rule of thumb most candidates follow — "always submit PDF" — isn't always correct. Some older ATS systems actually struggle with PDFs.

The fix

Read the job posting. If it specifies a format, use that format. If it doesn't:

• PDF is safe for most modern ATS and company career portals
• DOCX is safer for older enterprise ATS systems (common in large corporations)
• Never submit JPG, PNG, or any image format

If you're unsure — submit PDF, and mention in your cover letter that you're happy to provide DOCX if needed.

Mistake 6 — Putting Important Information in Headers and Footers

The problem

Many resume templates put the candidate's name, contact information, or LinkedIn URL in the document header.

ATS often skips headers and footers entirely. This means your contact information — the most critical part of your resume — might be invisible to the system.

Some candidates have had their resume rejected because the ATS couldn't find their name or email.

The fix

Put all contact information in the main body of the document. Your name, email, phone number, LinkedIn URL, GitHub, and location should all be in the normal text area — not in the document header.

MD Waliullah
waliullah@email.com | +880-1234-567890
linkedin.com/in/waliullah | github.com/waliullah
Dhaka, Bangladesh

Mistake 7 — Not Tailoring the Resume for Each Application

The problem

Sending the same resume to every job is the single biggest ATS mistake. A resume optimized for a "React Developer" role at a startup will score poorly for a "Frontend Engineer" role at a bank — even if the actual job is identical.

Different companies use different terminology. Different ATS systems are configured to look for different keywords. What scores 80% at one company might score 40% at another.

The fix

Tailor your resume for every application. This doesn't mean rewriting it from scratch — it means:

1. Reading the job description carefully
2. Identifying keywords you're missing
3. Adding those keywords to your summary and skills section
4. Adjusting one or two bullet points to mirror the job's language

This takes 10-15 minutes per application. It's the highest-ROI activity in your job search.

Shortcut: Use resume.codisim.com — paste the job description, upload your resume, and see exactly which keywords to add. The AI then rewrites your summary with those keywords included. Free, 12 analyses per week.

The Common Thread

All 7 mistakes come down to one thing: not thinking about how ATS reads your resume.

ATS doesn't appreciate good design. It doesn't read between the lines. It doesn't know that "JS wizard" means JavaScript developer. It scans for exact matches, scores them, and filters.

Once you understand that — fixing these mistakes becomes straightforward.

Your Action Plan

1. Check your resume format — single column, no tables, no images
2. Rewrite your summary with keywords from the target job
3. Add a comprehensive Skills section
4. Check your file format
5. Move contact info out of headers/footers
6. Tailor for each application

Start with step 1: upload your current resume at resume.codisim.com and get your ATS score. You'll see exactly which of these 7 mistakes you're making — in under 10 seconds.

Free. No credit card. 12 analyses per week.

Share this with someone who's been job hunting without results. One of these 7 mistakes is probably why.