System administrator screens are literal. Recruiters search Active Directory, Windows Server, Linux, PowerShell, and often the certification: RHCSA, CompTIA Network+, or a Microsoft admin exam. A resume that says "managed servers and user accounts" can be a real sysadmin background and still miss every one of those searches.
Name the systems you administer and the scripts you actually run. Then check the resume against a posting — the free checker lists the keywords that are missing.
Identity is the first filter on most corporate admin roles: Active Directory, Group Policy, Entra ID (Azure AD), and Microsoft 365. Write the task, not the product logo: "built Group Policy for mapped drives and password complexity across three sites." If you have moved tenants toward Entra ID, say both names once. Recruiters still search the old and the new.
The operating system is the second filter, and it is specific. "Linux" alone loses to "RHEL", "Ubuntu", or "Windows Server 2019/2022" when that is what the posting says. Put the distro or server version you support in the experience line, and keep a skills line for the family name so a broader search still matches.
PowerShell and Bash are searched as skills and as proof you don't click through every change. One concrete line is enough: "PowerShell script to stage monthly Windows patches and email a failure list" or "Bash check that alerts when a volume passes 85% full." Don't claim a language you couldn't walk through on a whiteboard.
Certifications belong in their own section, spelled the way the exam is published: CompTIA Network+, Red Hat Certified System Administrator (RHCSA), Microsoft 365 Administrator or Azure Administrator. Pair the abbreviation with the full name once. Some searches use "RHCSA" and some use the spelled-out title.
Paste your resume — and the job description if you have one — and get an instant ATS score with the exact keywords you're missing and what to fix first.
Check your resume free — no sign-up, instant score →Only if the posting lists it. When it does, the search is often the exact credential, so a missing line drops you out. When it doesn't, hands-on Active Directory, the OS, and a scripting example carry the screen. List a cert you hold; don't list one you plan to take as if you already have it.
Lead with whichever the job description asks for, and keep the other in a clear second line. A Windows-heavy posting still wants to see Linux if you have it, but burying Group Policy under a generic "systems" bullet means the Windows search never hits.
Stay at the layer you actually own: DNS, DHCP, VPN, VLANs, and firewall rules you requested or maintained. Name the vendor only if you configured it (pfSense, Cisco, Palo Alto). "Basic networking" matches nothing; "DNS and DHCP for three sites" does.