Sergei Kulnev

System Administrator / DevOps Engineer

Download Resume

Summary

System Administrator and DevOps Engineer with 10+ years of hands-on experience building and operating secure, resilient infrastructure in Linux/Windows environments. Designed and ran dev/test/prod platforms using Infrastructure as Code, automated CI/CD (Jenkins/GitLab), and containerization Docker. Strong in AWS, VMware ESXi/vCenter and Hyper‑V, networking, observability (Zabbix, Grafana, Prometheus), and PostgreSQL. Notable outcomes: −40% downtime via monitoring and audits, −$100K/year license savings after database/application server migration, company‑wide secure remote access, and a repeatable retail rollout process (50+ store openings).

Projects

Core Competencies

Containerization & Orchestration

Docker, Docker Swarm, Amazon ECS

Cloud & Virtualization

AWS (EC2, S3), Azure (AD, VMs, Storage, Virtual Desktop), Cloud.ru, VMware ESXi / vCenter, Hyper‑V, Proxmox, VirtualBox

IaC & Configuration

Terraform, Ansible

Monitoring & Observability

Zabbix, Grafana, Prometheus, Azure Monitor, CloudWatch

CI/CD & VCS

Jenkins, GitLab CI, Bitbucket, Groovy, PowerShell, Bash, Python, Ansible Playbooks

OS & Server Tools

Linux (CentOS, Debian, Ubuntu, RHEL, FreeBSD), Windows Server (2008–2019), Active Directory (GPO, DNS, DHCP, DFS, PS, FS, WSUS)

Networking & Security

Cisco, MikroTik (RouterOS/SwOS), VPNs, Routing & Switching, pfSense, FortiGate, IP/Subnetting, Firewalls

Databases & Messaging

PostgreSQL, MySQL, MS SQL Server, MongoDB, Oracle 12c/19c, ClickHouse, DB2, RabbitMQ, Kafka

Email & Telephony

Microsoft Exchange, Asterisk IP Telephony

Enterprise IT Tools

Squid Proxy, Nexus Repository, Rocket.Chat, Imaging & Deployment Tools, Asset Management Platforms

Professional Experience

System Administrator — TIRUS INC.

Chicago, IL • Apr 2024 – Present

  • Lead administration of Windows Server and Ubuntu systems supporting dispatch teams and development environments.
  • Manage AD (GPO, DNS, DHCP) and VPN/firewall across 60+ endpoints for secure remote access.
  • Provision and sustain VMware ESXi for dev/test of internal logistics software; partner with engineers on releases.
  • Monitor via Zabbix and Grafana, reducing unplanned downtime by 40% through proactive alerting and audits.
  • Train dispatchers and support staff; documented troubleshooting, cutting helpdesk tickets by 30%.
  • Migrate to hybrid model using AWS EC2/S3 for off‑site backups and scalable file access.

DevOps Engineer — SBERBANK

Moscow, RU • Feb 2021 – Dec 2023

  • Administered 80+ Ubuntu and Red Hat servers across dev/test/prod with hardening and streamlined backups (−60% recovery time).
  • Automated 95% of configuration and CI/CD deployment with Ansible and Jenkins (−50% test delivery time).
  • Migrated from Oracle & IBM WebSphere to PostgreSQL & WildFly, cutting licensing by $100K/year and improving performance.
  • Supported tool selection and procurement planning to improve scalability and reliability.

System Administrator — FODD

Moscow, RU • Mar 2020 – Feb 2021

  • Upgraded AD from Windows Server 2008 R2 to 2016 and enforced GPO standards (−30% login issues).
  • Deployed centralized monitoring with Zabbix (−25% unplanned downtime and critical incidents).
  • Implemented Azure AD and Azure Virtual Desktop to enable 100% remote work during shutdowns.
  • Launched a new data center from planning to deployment, integrating IP telephony and collaboration tools.

System Administrator — TRANS MANAGEMENT

Moscow, RU • Oct 2015 – Mar 2020

  • Scaled mixed Windows/Linux infrastructure: servers, virtualization, DNS/DHCP, backups, and identity.
  • Established MikroTik site‑to‑site VPNs and Asterisk IP telephony (−$10K/year telecom costs).
  • Deployed HP/Dell servers with CentOS, Debian, and Windows Server; introduced 1C/PostgreSQL on Linux (−30% downtime).
  • Handled IT procurement, vendor negotiations, and license compliance for 130+ endpoints.

System Administrator — MIRATORG

Moscow, RU • Aug 2012 – Sep 2015

  • Led nationwide rollout of new Miratorg retail stores — from SCS (structured cabling) layouts on floor plans to full server and network bring‑up.
  • Planned and implemented SCS; prepared and deployed server infrastructure (Windows Server 2008 R2/2012) with Hyper‑V where appropriate.
  • Configured network equipment and access: L2/L3 switching, Wi‑Fi, routing/VPN, DNS/DHCP, Active Directory, and file services.
  • Ensured secure access to corporate resources and integration with central systems; introduced basic monitoring and backup routines.
  • Authored rollout runbooks and checklists; contributed to IT operating procedures for stores.

Education

Bachelor of Computer Science and Information Security — Moscow Finance and Law University, Russia (2013)

Certifications

Get In Touch

The quickest way is to leave a message — I will reply shortly.