The resume mistakes that get a software engineer screened out share one shape.
On this page
A line a mediocre engineer at the same company could write truthfully.
Responsible for the backend services. Passionate about clean code. Improved application performance.
The fix is nearly always the same. Add the number, name your specific part, cut the adjective.
The 11 lines below come from resumes I read while screening engineering candidates. I changed the details, not the shape.
Which resume mistakes does a screener catch in 20 seconds?
About 6 or 7 lines, in roughly 20 seconds.
Your most recent role, the company, and 2 or 3 bullets under it.
Everything else is for a second pass that only happens if the first goes well.
A line that fits someone else’s resume unchanged burns one of those 7 slots.
1. “Responsible for the backend services”
Being responsible for something is a fact about your job title, not about you.
2 people can be responsible for the same services.
One rewrote the payment path. The other attended standups.
The line does not distinguish them.
Rewrite: “Rewrote the payment service to handle 3,000 requests a second, up from 400.”
2. “Passionate about writing clean code”
Everyone claims this. Nobody claims the opposite. A line that every candidate could write tells the reader nothing.
Worse, it burns one of the 6 or 7 lines a human will actually read.
Rewrite: delete it.
Care about code quality? Prove it with a number.
Coverage moved, incidents dropped, a review process you introduced.
3. “Worked in an Agile environment using Scrum”
Almost every engineer applying worked in Scrum. The line describes your employer’s meeting schedule.
Rewrite: delete.
Was the process work yours? Say what you changed.
“Cut the release cycle from 2 weeks to twice a week.” Then how: integration tests off the critical path.
4. “Improved application performance”
By how much? From what to what? For whom?
Without numbers this reads as a placeholder.
Hiring managers assume the number was unimpressive, or you would have written it.
Rewrite: “Cut p99 checkout latency from 1.8s to 340ms, by removing 3 synchronous calls.”
5. “Familiar with AWS, Azure, GCP, Kubernetes, Docker, Terraform, Ansible, Jenkins, Kafka, Redis…”
A 20-item skill list means 1 of 2 things.
Shallow exposure to all of them. Or deep skill in 3, buried.
Both readings hurt you, and the second is a self-inflicted wound.
Rewrite: group and cut. 4 categories, 4 or 5 items each. Nothing you would not want interviewing on.
6. “Team player with excellent communication skills”
Communication is a thing the interview tests directly. Claiming it in advance adds nothing and costs a line.
Rewrite: show it instead. “Wrote the design doc that 3 teams built against” carries its own evidence.
7. “Startup, Berlin. Software Engineer. 2022 to 2023.”
The company name means nothing to the reader and you gave them no scale.
I have no idea if that was 4 people or 400. A payments company or a games studio.
I will not look it up during a screening session.
Rewrite: add 1 line of context. “Fintech startup, 25 people, B2B payments in the DACH region. Second backend hire.”
8. “Contributed to the migration to microservices”
Contributed how? There were probably 15 people on that migration.
The reader wants your part. Vagueness here reads as borrowing credit, which is worse than a modest specific claim.
Rewrite: “Owned the extraction of the inventory service, including the dual-write period and the cutover. 4 weeks, no rollback.”
9. A skills section with progress bars
Python at 90%, Go at 70%. 90 percent of what?
Meaningless to a human, invisible to a parser. And a third of a page gone.
Progress bars also read as a design template rather than a considered document.
Rewrite: plain text lists, grouped.
10. “References available upon request”
Everyone knows. It has been assumed since the 1990s.
Rewrite: delete, and use the line for something that helps you.
11. 6 bullets on the job you left 5 years ago
Your oldest role is getting the same space as your current one. That inverts the reader’s priorities.
Recency dominates a screen. What you did in 2018 barely matters unless it is uniquely relevant.
Rewrite: current role gets 4 or 5 bullets. The one before it gets 2 or 3. Anything older than about 8 years gets 1 line, or a single “Earlier roles” block.
What do all 11 resume mistakes have in common?
Every one of them could appear on someone else’s resume without changing meaning. They describe a job rather than a person.
Responsible for names a title. Passionate about names a feeling nobody claims the opposite of. Contributed to names a group.
None of the 11 distinguishes you from the person sitting next to you.
How do you test for resume mistakes yourself?
Read each line. Could a mediocre engineer at your company write it truthfully?
If yes, the line is not working. Run it on every bullet, one at a time.
Expect to fail 6 to 10 of them.
The fix is the number, your specific part, and cutting the adjective.
What do you do with the space you free up?
You will free 6 to 10 lines. Use 2 or 3 on your most recent role.
Leave the rest as white space.
A page with room on it reads as confident.
A page with no margins reads as someone trying to convince you.
Convincing is what the deleted lines were doing.
Common questions
Should you ever use the word passionate on a resume?
No, and the same goes for driven, dedicated and enthusiastic. Nobody writes the opposite. The word carries no information and costs a line in a 20-second read. If the feeling is real, it shows up as something you did. Outside the job description, with a number attached.
What if you genuinely do not have numbers?
You almost certainly do, and you have not looked. Time before and after. Requests, users or markets. Incidents, coverage, deploy frequency, people hired or mentored. If the exact figure is confidential, use a ratio. “Cut provider cost by roughly a third” works. “Improved cost efficiency” does not.
How much space should an old job get?
Your current role gets 4 or 5 bullets. The one before it gets 2 or 3. Anything older than about 8 years gets a single line, or an “earlier roles” block. Recency dominates a screen. 6 bullets on a job you left in 2018 inverts the reader’s priorities.
Do skill progress bars actually hurt you?
Yes, in 3 ways. They mean nothing to a human. Python at 90% is 90 percent of an undefined thing. They are invisible to a parser. And they take up a third of a page. The page then reads as a template rather than a considered document.
What are the most common resume mistakes?
Describing the job instead of the work. “Responsible for the backend services” says nothing. The other repeat offenders are adjectives with no evidence. A skills list with 20 tools. Old jobs given as much space as recent ones. All of them waste a 20-second read.
The short version
Delete anything a mediocre engineer could also write. Add a number to every claim. Give each company 1 line of scale.
Spend your space on the last 3 years.
The full structure is in the software engineer resume that passes ATS and humans.
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