Hire the Best Unix System Administrators
in Ukraine

⭐️ Top Rated Plus - Top 3% Expert on Upwork 🕒 9000+ Working Hours ✅ 20+ Years of Expertise ✅ 100% Job Success ✅ 300+ Successful Projects Finished ✅ 5 Star Rating Hello, I'm Oleksandr. As a seasoned Linux System Administrator and DevOps Engineer with over 20 years of experience I specialize in delivering robust IT solutions that enhance operational efficiency and security. My expertise spans across various domains, including: ▪ DevOps & Automation: Successfully implemented automated provisioning using Ansible, streamlining deployment processes and reducing manual intervention. ▪ Linux & FreeBSD Maintenance: Managed and optimized server environments on CentOS, Debian, Ubuntu, RHEL, and FreeBSD, ensuring high availability and performance. ▪ Cloud Hosting: Deployed and maintained scalable cloud solutions on AWS, Azure, and DigitalOcean, enhancing infrastructure reliability and scalability. ▪ Virtualization: Utilized Docker, VirtualBox, and OpenVZ to create flexible and efficient virtual environments, supporting diverse application needs. ▪ Web & Database Servers: Configured and maintained Apache, Nginx, MySQL, PostgreSQL, and MongoDB servers, ensuring secure and efficient data handling. ▪ Networking & Security: Implemented secure networking solutions, including VPNs and firewalls, to protect sensitive data and maintain network integrity. I am committed to continuous improvement and staying abreast of the latest industry trends. My approach is rooted in ITIL best practices, ensuring incident management and business continuity planning are at the forefront of my work. Let's collaborate to drive your IT projects to success with innovative solutions and expert guidance.

## Professional Experience ### DevOps / Infrastructure Engineer Yeesshh 2018 – Present Sole DevOps/SRE responsible for full production infrastructure of ~50 web services and internal systems in digital advertising environment. **Infrastructure:** * 6 dedicated bare-metal servers hosted in OVHcloud * Proxmox single nodes and Proxmox cluster, altogether with ~30 virtual machines * Proxmox Backup Server, Custom NFS-based backup storage * Multi-region deployment (EU + Canada) * Internal VPN via Pritunl * Docker-based service deployments **Reliability & Operations:** * 24/7 on-call (30-minute critical SLA response) * ~99%+ uptime across production systems * Full Proxmox node disaster recovery (including restoration from backups) * Centralized monitoring via Zabbix * Centralized logging via Graylog * Security monitoring via Wazuh * Incident management via PagerDuty * Post-incident reporting and preventive improvements **Security & Compliance:** * DNS management (SPF, DKIM, DMARC) * DDoS mitigation using CSF/LFD, ModSecurity, mod_evasive * PCI compliance validation via Qualys (minimal adjustments required) * Regular patching & monthly backup validation **CI/CD & Automation:** * GitHub repositories * Jenkins pipelines for controlled deployments * Staging → testing → manual production release workflow * Limited Ansible automation (update & small maintenance scripts) **Modernization:** * Legacy OS upgrades * Partial containerization of services * Kubernetes - self-hosted proof-of-concept deployment (non-production) --- ### CloudOps / SysOps Engineer LCloud 2021 – 2023 Worked in AWS Partner environment supporting global enterprise and mid-size clients as L1 support. Environment: Amazon Web Services Responsibilities: * 24/7 production support (L1) * EC2, RDS, S3, IAM troubleshooting * Backup & restore procedures * Log analysis & incident escalation * Execution of infrastructure changes according to documentation * Exposure to IaC-managed environments --- ### Independent Linux Infrastructure Consultant 2012 – 2021 Provided infrastructure and system administration services for up to 100 international clients including web hosting providers. Experience includes: * Web hosting environments (Canada & Italy) * Email servers (Postfix/Exim) * DNS management * CMS deployments (WordPress, Drupal, Joomla) * Monitoring (Nagios, Zabbix) * Virtualization (Proxmox) * Security cleanup & WordPress malware removal * Redmine & GitLab environments --- ### Early Career (Condensed) Senior Linux Administrator – Retail network (250 employees) Network design, Linux desktop environment (60+ machines), POS equipment support, server infrastructure management. Additional system & network administration roles (2007–2012). --- ## Personal Technical Projects * Self-hosted AI workflow automation using n8n * Local LLM experimentation (LLaMA-based models compiled via llama.cpp) * Raspberry Pi lab (media server, backup storage, surveillance systems) * Mobile app development(dart) and backend infrastructure (Dockerized Node.js backend) --- ## Languages Ukrainian – Native Russian – Native English – Professional working Polish – Limited working Spanish - Learning

I am skilled network/system administrator with more than 10 years of experience. If you need: - Install and configure backup and monitoring system - Install and configure fast and reliable web-server - Configure your network equipment - Install and configure Mail System for the Email Marketing purposes or any other server side work, please feel free to contact me.

Based on my 30 years of experience in the field of IT, i am able to complete complex tasks of high difficulty. Working in international corporations allowed me to have a practice with productive and expensive systems. Contracts in the banking sector has taught confidentiality and responsibility and the importance of trust. My main qualification is in system administration. From the direct assembly of the server to the configuration of the operating system. Therefore i have expert knowledge of operation systems Windows\UNIX. Server OS: Microsoft Windows server, RedHat, Ubuntu, CentOS, PopOS, Debian, other Linux.. Cloud: Amazon Web Services AWS, Google cloud GCP, Oracle cloud, Microsoft Azure, IBM cloud.. Hosters: Digital Ocean, Hetzner.. Virtualization: Hyper-V, VMWare, VirtualBox, KVM, Proxmox.. Emergency problem resolving. Web, VPN, VPS, Cloud, Virtualization. Hardware troubleshoting and repair. Security networking. Infrastructure protection. BIOS\FW recovering, updating.

Downtime costs the average enterprise $540,000 per hour. When your platform goes down, you lose revenue, trust, and engineering hours fighting fires instead of building features. I implement deep observability and self-healing systems to ensure your platform stays up - no matter what. With 10+ years in DevOps and Site Reliability Engineering, I bring the broadest monitoring and operations stack you will find: Zabbix · Graphite · Sumo Logic · Prometheus · Grafana · Datadog · ELK Stack - combined with deep Linux/Unix infrastructure expertise since 2012. I treat operations as a software problem. My focus: Deep Observability, Toil Reduction, and Incident Command. What I delivered for my clients: 🔹 GetChecked (US Blockchain/Cybersecurity): Maintained and upgraded Hyperledger Fabric network across multi-cloud infrastructure (AWS + DigitalOcean + bare metal). Implemented full backup, disaster recovery, and business continuity strategy in a strictly regulated government-affiliated environment. Zero critical incidents during major Fabric version upgrade. 🔹 Simployer/Alexis HR (Sweden SaaS): Maintained GCP Kubernetes clusters for a post-merger HR platform operating across two companies. Optimized CI/CD pipelines with GitHub Actions and GCP Cloud Build, implemented monitoring with NewRelic + Prometheus + Squadcast - ensuring consistent SaaS reliability during organizational transition. 🔹 iLost (Netherlands): Resolved complex OpenSearch performance issues causing worker timeouts and system instability. Debugged SSL/network connection failures, managed cluster migration and reindexing, handled Karpenter node management alerts - restored platform stability under production load. 🔹 ADF (US Digital Forensics): Modernized legacy C++ desktop systems and migrated workloads to Azure cloud. Implemented Docker/Kubernetes orchestration, optimized CI/CD pipelines, improved logging and failover mechanisms - handling multi-environment deployments with zero data loss. My SRE approach: 🔹 Zero Trust Architecture · IAM · RBAC · SELinux security hardening 🔹 Blameless Post-Mortems and systematic incident command 🔹 Proactive toil reduction - automate the repetitive tasks before it becomes an outage 🔹 Multi-cloud reliability: AWS · GCP · Azure · DigitalOcean · Bare Metal 🔹 Managed SRE & 24/7 Support: SLA-backed monitoring, on-call incident response, and continuous infrastructure health-checks Technologies: Prometheus · Grafana · Datadog · ELK Stack · Zabbix · Sumo Logic · PagerDuty · Terraform · Kubernetes · Helm · HashiCorp Vault · Jenkins · GitHub Actions Compliance: SOC 2 · GDPR · HIPAA · Government-grade security requirements Don't wait for the next crash. Click Invite to discuss your SLAs and get to Four Nines.

Hello there! I'm experienced Linux and DevOps Specialist with a strong background as a Linux System Administrator 🧑‍💻. I’m working for 5 years in the hosting industry, configuring server infrastructure, helping clients manage servers, troubleshoot issues, and keep their websites running smoothly. If you're looking to set up, migrate, secure, or fix your web infrastructure - I'm ready to jump in and help 🚀 🛠️ My technical skills include: - 🐧 Linux systems (CentOS, Ubuntu, Debian, AlmaLinux) - 🐳 Containers: Docker & Podman - 🔄 Backup & Recovery - 🧾 Certified cPanel/WHM Administrator - full control over account management, backups, server tuning, and issue resolution - 🔧 Version control with Git - collaborative and safe development workflows - 🔐 SSH & FTP configuration - 🛜 Troubleshooting & Logs - 🌐 Networking (iptables, nftables) - 🕒 Cron job management - 📜 Bash scripting - 🌍 DNS setup and troubleshooting - 🔄 Website & email migrations - 📧 Mail server configuration (Exim, Postfix, etc.) - 🧩 Web server management (Apache, Nginx, CloudLinux) ✅ Why work with me? ✅ You'll get administrator-level expertise ✅ I provide clear, human answers to tech questions ✅ Available for ongoing support & consultations ✅ I don’t just assist — I dig deep and solve problems 🤓 Let’s make your infrastructure fast, secure, and worry-free =)