A resume with a colored sidebar for skills and a main column for experience looks good to a human, but many ATS parsers read a PDF or DOCX by extracting text in the order it appears in the underlying document structure — not by following the visual layout a person sees. Depending on how the columns were built, that extraction can merge the sidebar and main column into one jumbled stream, putting your "Python, Go, Kubernetes" skills list in the middle of a job description, or scrambling dates away from the roles they belong to.

That risk is exactly why the classic reverse-chronological format — name and contact block, then Summary, Skills, Experience, Projects, Education, in that order, one column, top to bottom — remains what large-company ATS deployments and government application portals explicitly recommend. It isn't a stylistic preference; it's the layout least likely to be misread by software that was never guaranteed to render the resume visually at all.

None of the three templates here use CSS columns, tables, or absolutely-positioned sidebars for content ordering. Visual differences between them come from typography, spacing, and color — the DOM order, and therefore the text order a parser sees, is identical single-column flow in all three.

The bullets that work best start with a strong past-tense verb, state what you built or fixed, and end with a number: "Cut invoice processing time from 4 hours to 12 minutes by replacing a nightly batch job with an event-driven pipeline." That sentence gives a human reader the story in one line and gives an ATS or LLM screener concrete keywords (event-driven, pipeline) attached to a measurable result, rather than a vague claim like "responsible for backend systems."

Mirror the language in the job posting where it's honestly true. If the posting says "distributed systems" and your bullet says "microservices," a keyword-matching ATS may not connect the two even though a person would. This isn't about stuffing keywords — it's about not making the parser guess at a synonym when the exact term is what's being searched for.

Keep each bullet to one line if you can, two at most. A resume drowning in four-line paragraphs under every job reads as padding to a recruiter doing a 15-second first pass, and long paragraphs are also where ATS text extraction is most likely to garble line breaks.