Linux Platform Engineering
RHEL & Ubuntu at scale — golden images with Packer, IPA, Satellite, patching, hardening, third-line ops.
$ whoami → polat-consultancy
Sinan PolatLinux & Cloud Consultant
15+ years building, automating and operating Linux, OpenStack, Ceph and Kubernetes platforms across Dutch government and enterprise.
01 / About
Hands-on, since 2009.
I'm a freelance Linux and Cloud consultant with 15+ years of hands-on experience managing, troubleshooting and migrating Linux-based systems at scale.
I design, deliver and operate OpenStack and Ceph environments, run Kubernetes (Talos, OpenShift) workloads, and automate everything I can with Ansible, Python and Terraform.
I work comfortably with networking gear from my ISP/hosting background, and communicate clearly with both technical teams and non-technical stakeholders.
02 / Services
What I do for clients.
Independent freelance engagements, typically embedded in platform or infrastructure teams.
Cloud & Virtualization
OpenStack and Ceph design, delivery and upgrades. Red Hat Virtualization, AWX, VMware, NSX-T migrations.
Containers & Kubernetes
Production Kubernetes on Talos and OpenShift. Helm, Flux CD, Vault, container migration from VMs.
Automation & CI/CD
Ansible/AWX, Terraform/Terragrunt, Jenkins, Python. Repeatable deploys, monitoring with Prometheus/Grafana.
03 / Stack
Tools I reach for.
Pulled from the platforms I run today and have built in the past.
Operating systems
RHEL 5/6/7/8/9/10CentOSDebianUbuntuFreeBSD
Cloud & virtualization
Red Hat OpenStackRed Hat VirtualizationVMwareNSX-TAzureAWS
Containers
KubernetesTalosRed Hat OpenShiftDockerPodmanHelm
IaC & automation
AnsibleAWXTerraformTerragruntPackerPuppet
CI/CD
JenkinsGitLabBitBucketGitFlux CD
Observability
PrometheusThanosGrafanaZabbixSensuCheck MKElasticsearchKibanaFluentd
Storage & data
Red Hat Ceph StorageMySQL / MariaDBInfluxDBNFSLVM
Identity & tooling
(Free)IPARed Hat SatelliteHashiCorp VaultPKI
Networking
Juniper EXCisco ACIFortigateNginxApachePowerDNSBINDPostfix
Languages & methods
BashPythonJSONAgileKanban
04 / Certifications
Certified, repeatedly.
15 certifications and trainings across Red Hat, Kubernetes, AWS, LPI, Juniper and Cisco.
- Jul 2025Certified Kubernetes Administrator (CKA)
- Oct 2022Red Hat Certified Specialist in Containers and Kubernetes (EX180)
- Dec 2019PCEP — Certified Entry-Level Python Programmer
- Nov 2019Red Hat Certified Specialist in Ansible Automation (EX407)
- Oct 2019AWS Certified Cloud Practitioner (CLF-C01)
- Nov 2018Red Hat Certified Engineer (RHCE 7, EX300)
- May 2018Juniper Junos Intermediate Routing
- May 2018Juniper Junos MPLS Fundamentals
- Feb 2018Red Hat Certified Specialist in Red Hat OpenStack (EX210)
- Sep 2017Cisco Application Centric Infrastructure (ACI)
- May 2017Red Hat Ansible Automation Foundations
- Sep 2016Red Hat Certified System Administrator (RHCSA 7, EX200)
- Jul 2015Linux Professional Institute Certified 201 (LPIC-2)
- Oct 2010Linux Professional Institute Certified 102
- Oct 2010Linux Professional Institute Certified 101
05 / Experience
Where I've built and operated.
A timeline of roles, mostly in Dutch government and enterprise infrastructure teams.
Apr 2024 – present
Platform Infra Engineer· Netherlands Forensic Institute (NFI)
Maintain and optimize OpenStack, Ceph, Kubernetes (Talos) and Linux environments. Day-to-day work in Git, Jenkins, Ansible, Terraform and Python.
LinuxUbuntuKubernetesTalosOpenStackCephAnsiblePythonGitBitBucketFlux CDTerraformTerragruntJenkinsPrometheusGrafanaHelmVaultApr 2024 – present · part-time
Linux Specialist· De Connectie
Design and maintain RHEL golden images with Packer. Automate provisioning by integrating VMware with Red Hat Satellite. Build Ansible roles orchestrated via AWX.
RHEL 8/9/10AWXVMwareGitLabRed Hat IPAAnsiblePackerSatelliteAug 2023 – Apr 2024
Linux Specialist· Ministerie van Defensie
Designed and deployed the Linux building block. Streamlined operations through extensive Ansible automation.
RHEL 7/8AnsibleGitLabPythonDockerGrafanaKibanaElasticsearchNagiosJan 2022 – Aug 2023
Senior Linux / DevOps Engineer· Politie
Customers & Roles team: wrote and maintained Puppet roles/profiles and Ansible playbooks. Later in Shared Infra, owning the tooling used by all Linux teams.
RHEL 6/7/8SatelliteIPAAnsiblePuppetVMwareGitLabPythonBashIcingaMar 2021 – Feb 2023
Senior DevOps Engineer· Doculayer
Owned CI/CD pipelines deploying the Doculayer app to Kubernetes on Azure and OpenStack. Maintained Jenkins jobs, Ansible playbooks and Helm charts. Built monitoring with Prometheus, Thanos, Grafana and EFK.
AzureOpenStackKubernetesJenkinsHelmVaultPrometheusThanosEFKGrafanaApr 2020 – Mar 2021
Senior Linux Engineer· Rijkswaterstaat
3rd-line engineer in Linux Operations, responsible for ~3000 VMs (RHEL 5–8). Automated patching with Ansible/AWX. Monitoring via Zabbix.
RHEL 5/6/7/8SatelliteIPAAWXAnsiblePuppetVMwareNSX-TZabbixJul 2018 – Sep 2020
Linux / Cloud Specialist & Lead Engineer· Hot Potatoes Managed Hosting
Designed and delivered 2 OpenStack + 2 Ceph clusters. Upgraded 2 OpenStack clusters, decommissioned and migrated one. Migrated VM-based apps to containers on OpenShift, and KVM VMs to Red Hat Virtualization.
RHOSP 10/12/13CephRHVOpenShiftSatelliteIPAAnsibleTerraformJenkinsJuniperCisco ACIDec 2016 – Jun 2018
Linux / Cloud Specialist· EBPI
Delivered virtual servers and middleware. Wrote Ansible playbooks. Managed Red Hat OpenStack, Satellite, IPA, RHV and Gluster.
RHEL 6/7UbuntuOpenStackCephSatelliteIPARHVAnsibleCheck MKGrafanaMar 2009 – Nov 2016
(Senior) Technical Linux Engineer· Leaseweb
Team lead for 5 Linux support engineers. 2nd- and 3rd-line Linux support. Provisioned physical and virtual servers; managed Juniper switching.
CentOSDebianUbuntuFreeBSDPleskcPanelDellHP ProliantJuniperSep 2007 – Feb 2009
FrontOffice ICT· Grafisch Lyceum Rotterdam
ICT support for teachers. Installed and maintained Windows and macOS workstations and lab hardware.
WindowsmacOSDellHPiMac
06 / Security research
Responsible disclosure.
Findings reported through coordinated disclosure programs and open-source security advisories.
Moderate
CVE-2026-55836
Path traversal / arbitrary server-file read in Open Zaak Documenten API
Open Zaak
Reported a path-traversal vulnerability in the Documenten API's document import (bestandspad), allowing arbitrary server-file reads. Patched in 1.27.2, 1.28.2 and 1.29.0.
GHSA-x5cj-23hr-5r54Acknowledged
CVD
Coordinated Vulnerability Disclosure — Dutch government
Rijksoverheid
Identified and responsibly disclosed a security vulnerability in a Dutch government system under the CVD program, resulting in official acknowledgment.
07 / Contact
Let's talk.
Available for freelance Linux, cloud and platform engagements in the Netherlands.
sinan@polatconsultancy.nl
Phone
06 818 54 997
linkedin.com/in/sinanpolat
Based in
Rijswijk, NL
Polat Consultancy · 36 h/week
DutchNative
EnglishGood — conversation & reading
TurkishGood — conversation & reading