Top 12 System Administrator Skills to Put on Your Resume

Systems hum. Networks breathe. Behind it all, system administrators keep the pulse steady, untangling snarls and steering uptime. Put the right 12 skills on your resume and you don’t just look capable—you look indispensable.

System Administrator Skills

1. Linux/Unix
2. Windows Server
3. VMware ESXi
4. Active Directory
5. PowerShell
6. Bash Scripting
7. Cisco Networking
8. AWS/Azure
9. Docker/Kubernetes
10. SQL Server
11. Ansible/Chef
12. Nagios/Zabbix

1. Linux/Unix

Linux/Unix spans a family of stable, secure, efficient operating systems built for serious work—servers, networks, containers, you name it. Admins live here, quietly making everything run.

Why It’s Important

Rock-solid uptime, fine-grained control, strong security models, and scripting everywhere. Linux/Unix lets admins shape systems to fit the job, not the other way around.

How to Improve Linux/Unix Skills

1. Patch relentlessly: Keep kernels and packages current. Use apt (Debian/Ubuntu), dnf (RHEL/Fedora/Alma/Rocky), zypper (SUSE), or pacman (Arch). Automate reboots where needed.

2. Watch performance: Lean on top, htop, vmstat, iotop, sar, nmon. Feed metrics into Prometheus/Grafana or similar so you see trouble coming.

3. Harden the box: Use firewalld or nftables (and iptables where legacy persists). Enforce SELinux or AppArmor, not “permissive forever.” Fail2Ban for brute-force noise.

4. Back up like you mean it: Scripted, tested backups with rsync, BorgBackup, Restic, or Bacula. Encrypt. Rotate. Verify restores regularly.

5. Tune smartly: Adjust /etc/sysctl.conf for networking and memory. Use tuned profiles where available. Don’t over-tweak without data.

6. Strong SSH: Use ed25519 keys, disable password logins, restrict root, consider FIDO2 keys, and enforce MFA where possible.

7. Automate the grind: Ansible, Puppet, Chef, or Salt for repeatable builds and drift repair.

8. Logs with teeth: journalctl, rsyslog/syslog-ng, and centralization via ELK/OpenSearch or Graylog. Parse, alert, retain sanely.

9. Reduce the surface: Disable services you don’t need. With systemd, systemctl disable --now is your friend.

10. Network sanity: Encrypt in transit (SSH, TLS). Forensics with tcpdump and Wireshark. Scan proactively with nmap.

Small, steady improvements compound. Your estate gets faster, quieter, safer.

How to Display Linux/Unix Skills on Your Resume

2. Windows Server

Microsoft’s server platform for identity, file/print, virtualization, and application hosting. It anchors many enterprise networks.

Why It’s Important

It centralizes access and services, scales well, and integrates neatly with enterprise tooling—making operations manageable instead of chaotic.

How to Improve Windows Server Skills

1. Patch and plan: Apply updates on cadence. Use WSUS or modern management to coordinate and stagger reboots.

2. Encrypt at rest: Enable BitLocker with TPM, escrow recovery keys, test recovery flows.

3. Measure first: Use Performance Monitor, Resource Monitor, and Windows Performance Recorder/Analyzer to hunt bottlenecks.

4. Minimal roles: Install only what’s needed. Fewer features, smaller attack surface.

5. Backups you trust: Windows Server Backup or VSS-aware solutions. Offsite, offline, and restore tests—no surprises.

6. Baseline security: Apply Microsoft security baselines, enforce LAPS/Windows LAPS for local admin password rotation, and harden SMB and TLS settings.

7. Network discipline: Right-size NIC teaming, QoS where needed, and tight Windows Defender Firewall rules.

8. AD care: Clean stale objects, validate replication, keep GPOs lean and documented.

9. See the signals: Centralize logs with Windows Event Forwarding or a SIEM. Create alerts for auth anomalies and service failures.

10. Automate with PowerShell: Idempotent scripts for provisioning, compliance checks, and repeatable fixes.

How to Display Windows Server Skills on Your Resume

3. VMware ESXi

A bare-metal hypervisor that lets you run many virtual machines on one physical host. Consolidation with control.

Why It’s Important

Virtualization trims hardware sprawl, adds resiliency, and makes disaster recovery feasible without a small army.

How to Improve VMware ESXi Skills

1. Keep current: Patch ESXi hosts and vCenter. Use Lifecycle Manager to standardize images and drivers.

2. Right-size resources: Tune CPU/Memory reservations and shares. Avoid overcommitting where latency kills.

3. Storage matters: Align datastores to workload needs (vSAN, VMFS, NFS). Monitor latency, IOPS, and queue depths.

4. Network resilience: NIC teaming, proper VLANs, and dedicated VMkernel interfaces for management, vMotion, and storage traffic.

5. Security hardening: Secure Boot, TPM 2.0 attestation, lockdown mode, and strict RBAC. Limit direct host access.

6. Automate: PowerCLI for builds, audits, and lifecycle. Scripts save weekends.

7. Test recovery: Snapshot with care, use backup integrations, and validate restore/DR runbooks.

How to Display VMware ESXi Skills on Your Resume

4. Active Directory

Microsoft’s on-premises directory and identity backbone for Windows domains—authentication, authorization, and policy all in one place.

Why It’s Important

Centralized identity and policy control keep large environments sane, secure, and manageable. It’s the keys to the kingdom—treat it that way.

How to Improve Active Directory Skills

1. Least privilege, for real: Tiered administration, dedicated admin accounts, and Privileged Access Workstations. No daily browsing with domain admin credentials.

2. Strong auth: MFA where possible, smartcards/FIDO2 for admins, gMSAs for services, and minimize NTLM usage in favor of modern Kerberos.

3. Audit and alert: Enable advanced auditing, centralize events, and watch for password sprays, DC sync attempts, and GPO tampering.

4. Healthy replication: Verify sites/subnets align with your WAN. Monitor replication latency. Use dcdiag and repadmin regularly.

5. Backup the right way: Frequent system state backups of domain controllers. Practice authoritative and non-authoritative restores.

6. GPO hygiene: Consolidate policies, use an ADMX Central Store, minimize WMI filters and loopback unless necessary.

7. Harden DCs: Reduce installed roles, restrict inbound access, protect LSASS, and deploy Defender/EDR with exclusions configured correctly.

8. Hybrid clarity: If synced with Microsoft Entra ID, keep source-of-truth clean, scope sync deliberately, and guard privileged cloud roles.

9. Regular cleanups: Retire stale users, computers, and SPNs. Review group nesting and delegated OU rights.

How to Display Active Directory Skills on Your Resume

5. PowerShell

Automation on Windows (and beyond). A shell plus a scripting language with objects, not just text—great for repeatable operations.

Why It’s Important

It turns hours into minutes. Fleet changes done once, done right, done the same every time.

How to Improve PowerShell Skills

1. Foundations first: Understand objects, pipelines, cmdlets, and providers. Discoverability with Get-Help and Get-Command.

2. Error handling: Use try/catch/finally, structured errors, and -ErrorAction sanely.

3. Modules and reuse: Package functions into modules. Prefer the PowerShell Gallery when appropriate; version and sign your code.

4. Remoting and DSC: Use PowerShell Remoting to fan out. Desired State Configuration for drift control.

5. Test and lint: Pester for unit/integration tests. ScriptAnalyzer for style and safety. CI to enforce it.

6. Version control: Git for everything. Branch, review, and tag releases.

7. Secrets done right: SecretManagement, vault integrations, and no hardcoded credentials. Ever.

8. Move to PowerShell 7+: Cross-platform, faster, modern. Keep Windows PowerShell for legacy when needed.

How to Display PowerShell Skills on Your Resume

6. Bash Scripting

The glue of Unix-like systems. Chain commands, automate workflows, and make the OS jump on cue.

Why It’s Important

When you manage many boxes, Bash chops down toil—fewer clicks, fewer mistakes, more consistency.

How to Improve Bash Scripting Skills

1. Safe defaults: Start scripts with set -euo pipefail and sensible IFS. Quote variables. Avoid parsing fragile output.

2. Structure matters: Use functions, getopts for flags, and clear usage messages. Log verbosely when running unattended.

3. Debug without guessing: set -x, custom PS4, and trace suspicious sections.

4. Lint and format: ShellCheck to catch footguns, shfmt for readability.

5. Know your toolbox: Lean on awk, sed, grep, and xargs. When a script grows too big, consider Python.

6. Idempotence: Write scripts that can run twice without breaking things. Check before changing.

7. Keep learning: Refactor old scripts. Read others’ code. Borrow patterns that age well.

How to Display Bash Scripting Skills on Your Resume

7. Cisco Networking

Routers, switches, firewalls, wireless—Cisco gear runs a massive chunk of the world’s networks across IOS XE, NX‑OS, and IOS XR.

Why It’s Important

Reliable, well-designed networks keep apps snappy and users happy. When the network stumbles, everything else looks broken.

How to Improve Cisco Networking Skills

1. Know the platforms: Grasp differences between Catalyst, Nexus, and ISR/ASR families. Pick the right box for the job.

2. Design first: Hierarchical design, consistent VLAN/VXLAN strategy, and clean IP addressing. Document like your future self depends on it.

3. Secure the edge: SNMPv3, SSH only, AAA with central auth, and hardened management planes. Prune unused ports and protocols.

4. Monitor everything: NetFlow/IPFIX, syslog, SNMP traps, and proactive thresholds. Dashboards that surface anomalies fast.

5. Automate: Ansible, pyATS, NETCONF/RESTCONF. Generate configs from source of truth and push changes safely.

6. Resiliency: EtherChannel, HSRP/VRRP, ECMP. Know convergence behavior before it’s 2 a.m.

7. QoS with intent: Classify precisely, police where needed, and keep latency-sensitive traffic protected.

8. Lab often: Packet Tracer, CML, or virtual topologies. Break things when it doesn’t hurt.

9. Lifecycle: Track IOS/NX‑OS versions, field notices, and hardware end-of-life. Plan upgrades, don’t react to them.

How to Display Cisco Networking Skills on Your Resume

8. AWS/Azure

The two big cloud platforms give you elastic compute, storage, networking, identity, and a buffet of managed services.

Why It’s Important

Scale when demand spikes, shrink when it calms. Pay for what you use, automate it all, and build resilient systems across regions.

How to Improve AWS/Azure Skills

AWS

1. Core fluency: EC2, S3, RDS, VPC, IAM. Understand security groups, NACLs, and least-privilege policies cold.

2. Operations clarity: CloudWatch, CloudTrail, Config, Systems Manager. Build alarms and automated remediation.

3. Infrastructure as Code: CloudFormation or Terraform for repeatable environments. Pipelines for drift detection and promotions.

4. Security posture: KMS everywhere, private subnets, VPC endpoints, well-scoped roles, and strong key rotation.

5. Cost control: Budgets, tagging, rightsizing, and lifecycle policies. Kill idle.

Azure

1. Core fluency: Azure VMs, Storage, Azure SQL, VNets, and Microsoft Entra ID for identity.

2. Governance: Azure Policy, role-based access, management groups, and good tagging from day one.

3. Observability: Azure Monitor, Log Analytics, and action groups for alerting. Baselines that catch drift.

4. Automation: ARM/Bicep or Terraform, plus Automation/Functions for scheduled tasks. GitOps patterns where it fits.

5. Security and continuity: Private endpoints, Key Vault, Defender plans, and tested backup/DR runbooks.

How to Display AWS/Azure Skills on Your Resume

9. Docker/Kubernetes

Docker packages apps into portable containers. Kubernetes orchestrates those containers at scale across clusters.

Why It’s Important

Consistent environments, faster deployments, and elastic scaling. Fewer “works on my machine” moments.

How to Improve Docker/Kubernetes Skills

Docker

• Core commands: Images, containers, networks, and volumes. Clean layers, small images, clear tagging.

• Dockerfiles that age well: Multi-stage builds, pinned versions, non-root users, and explicit HEALTHCHECK.

• Security: Limit capabilities, read-only filesystems, scan images, and sign artifacts. Keep secrets out of images.

Kubernetes

• Operate the basics: Pods, Deployments, Services, Ingress, and ConfigMap/Secret handling. Master kubectl.

• Policies and safety: RBAC least privilege, Pod Security Standards, and network policies (Calico/Cilium-style thinking).

• Right resources: Requests/limits, liveness/readiness/startup probes, and graceful rollouts. Autoscaling with HPA/VPA where appropriate.

• Packaging: Helm or Kustomize for repeatability and overlays. Keep values documented.

• Observability: Prometheus and Grafana for metrics; EFK/OpenSearch for logs. Alert on SLOs, not vibes.

Continuous Learning

• Hands-on: Spin up kind or minikube locally. Break and fix. Repeat.

• Platform breadth: Learn how cloud-managed Kubernetes differs (EKS/AKS/GKE). Cluster autoscaler behavior matters.

• Supply chain: SBOMs, image provenance, and admission control to block risky workloads.

How to Display Docker/Kubernetes Skills on Your Resume

10. SQL Server

Microsoft’s relational database engine for transactional systems, analytics, and everything in between.

Why It’s Important

Data sits at the center. SQL Server keeps it consistent, fast, and recoverable when things go sideways.

How to Improve SQL Server Skills

1. Maintenance plans that matter: Update stats, rebuild or reorganize indexes as needed, and check DB integrity (DBCC CHECKDB) on schedule.

2. Index strategy: Remove unused indexes, add helpful ones, and avoid overlap. Watch write amplification.

3. Query tuning: Use Query Store and execution plans to fix the true hot spots. Parameter sniffing awareness helps.

4. Blockers and deadlocks: Monitor waits, identify blocking chains, and add proper indexing or retry logic to reduce deadlocks.

5. Server configuration: Tune MAXDOP, Cost Threshold for Parallelism, memory caps, and optimize tempdb layout.

6. Resource governance: Resource Governor to keep noisy neighbors from stealing the show.

7. Backups and restores: Full/diff/log strategy, tested restores, and RPO/RTO aligned with the business. Encrypt backups.

8. Stay current: Apply CUs, plan upgrades, and leverage new engine features that reduce operational friction.

How to Display SQL Server Skills on Your Resume

11. Ansible/Chef

Two proven platforms for configuration management and automation. Ansible is agentless with YAML playbooks; Chef uses agents with Ruby recipes. Both aim for consistent, repeatable infrastructure.

Why It’s Important

Manual changes drift. Automation brings order—one source of truth, one path to “known good.”

How to Improve Ansible/Chef Skills

1. Core concepts: For Ansible—playbooks, roles, inventories, collections. For Chef—recipes, cookbooks, resources, policies.

2. Idempotent code: Write tasks/resources that converge gracefully. Small, composable units beat monoliths.

3. Testing: Molecule (Ansible) or Test Kitchen (Chef) with InSpec-style checks. Bake tests into CI.

4. Secrets management: Ansible Vault or Chef Vault. Rotate keys and keep secrets out of repos.

5. Orchestration: Use AWX/Ansible Automation Platform or Chef Infra Server/Automate for RBAC, scheduling, and reporting.

6. Patterns that scale: Variables and group vars, role defaults, policyfiles/environments, and clear naming. Documentation in-repo.

7. Extend thoughtfully: Custom modules/resources where needed, with tests and versioning.

How to Display Ansible/Chef Skills on Your Resume

12. Nagios/Zabbix

Open-source monitoring mainstays. They watch hosts, services, and applications, trigger alerts, and paint the health picture you need.

Why It’s Important

Early warnings mean smaller incidents. Good telemetry turns guesswork into action.

How to Improve Nagios/Zabbix Skills

Nagios

1. Lean configs: Templatize hosts and services, reduce duplication, and keep naming consistent.

2. Distributed checks: Offload work to workers/satellites for scale and locality.

3. Efficient plugins: Use fast, purpose-built checks. Wrap custom scripts where needed, with timeouts and clear exit codes.

4. Event handlers: Auto-remediate known issues—restart services, clear stuck states, or open tickets.

5. Lifecycle care: Update regularly, archive stale objects, and validate notification paths.

Zabbix

1. Server tuning: Adjust pollers, caches, and history settings to match load. Profile, then tweak.

2. Templates and discovery: Use LLD and vendor templates as a base; customize to cut noise.

3. Proxies for reach: Place proxies near remote sites to reduce latency and central load.

4. Data hygiene: Tune housekeeping, prune unused items, and set sensible history/trend retention. Consider TimescaleDB for scale.

5. APIs and dashboards: Automate onboarding, mute storms during maintenance, and build views that ops can act on.

How to Display Nagios/Zabbix Skills on Your Resume