Serge Kulnev

Administer Windows Server and Ubuntu infrastructure across 60+ endpoints, supporting dispatch teams, developers, and field drivers for a logistics operations company. Manage Active Directory (GPO/DNS/DHCP), VPN and firewall systems, and VMware ESXi environments used for internal software development and testing.

• Provision and sustain VMware ESXi environments for development and testing of internal software used by truck drivers to track loads and earnings and access logistics tools. Collaborate with the engineering team to deploy stable releases across operational units.
• Monitor infrastructure performance with Zabbix and Grafana, reducing unplanned downtime by 40% through proactive alerting and regular audits.
• Migrated internal systems to a hybrid model using AWS EC2 and S3, enabling off-site backups and scalable file access for dispatch ops.
• Train dispatchers and support staff on IT tools and logistics systems, and document troubleshooting workflows to strengthen onboarding and cut helpdesk tickets by 30%.

Environment: Windows Server, Ubuntu, VMware ESXi, AWS (EC2/S3), Active Directory (GPO/DNS/DHCP), Zabbix, Grafana, VPN/firewall.

Worked within the core banking platform infrastructure team of 50+ (developers, QA, analysts, and engineering leads). Administered a hybrid Linux environment supporting development, testing, and production workloads for internal banking systems.

• Administered 80+ Ubuntu and Red Hat Enterprise Linux servers across dev, test, and production environments. Hardened systems and streamlined backup processes, reducing recovery time by 60%.
• Automated 95% of system configuration and CI/CD pipeline deployment using Ansible and Jenkins. Reduced manual setup errors and accelerated test delivery by 50%.
• Deployed and maintained containerized workloads using Docker and Docker Swarm, standardizing service delivery across environments.
• Built and maintained observability stack with Zabbix, Grafana, and Prometheus for proactive alerting and infrastructure health visibility.
• Managed RabbitMQ messaging infrastructure supporting asynchronous communication between banking services.
• Engineered migration from Oracle Database and IBM WebSphere to PostgreSQL and WildFly, cutting licensing costs by $100K/year and improving system performance.
• Contributed to infrastructure tooling decisions and procurement planning to support platform scalability and long-term reliability.

Environment: Red Hat Enterprise Linux, Ubuntu, Ansible, Jenkins, Docker, Docker Swarm, RabbitMQ, PostgreSQL, WildFly, Zabbix, Grafana, Prometheus, Oracle 19c, IBM WebSphere (legacy), Bash, Python, Git.

Part of a 7-person IT team at a premium construction and engineering general contractor (high-end residential, hospitality, and commercial real estate in Moscow, founded 1997), supporting 100+ servers and 1,000+ users across corporate offices and construction sites.

• Led Active Directory upgrade from Windows Server 2008 R2 to 2016 and enforced GPO security standards, improving security posture and reducing login issues by 30%.
• Deployed centralized Zabbix monitoring across 100+ servers, reducing unplanned downtime and critical incidents by 25%.
• Administered VMware vSphere / vCenter virtualization environment hosting production and internal services, managing VM provisioning, snapshots, and resource allocation.
• Built hybrid remote work infrastructure during COVID-19 lockdowns: implemented Azure AD and Azure Virtual Desktop for office staff, combined with site-to-site and client VPN access for on-site workers. Enabled 100% business continuity for 1,000+ users during pandemic shutdowns.
• Led launch of a new colocated data center: planned rack layout and prepared cost estimates, coordinated installation, migrated production servers into a leased rack at the facility, and integrated Asterisk IP telephony and collaboration tools.
• Designed and maintained backup infrastructure and VPN access for remote engineers, project managers, and construction site offices.

Environment: Windows Server 2008 R2 / 2016, Active Directory (GPO/DNS/DHCP), VMware vSphere / vCenter, Azure AD, Azure Virtual Desktop, Zabbix, Asterisk IP telephony, VPN infrastructure.

Managed IT infrastructure for an engineering, project management, and energy infrastructure firm — mixed Windows/Linux environments supporting 130+ endpoints through a period of rapid company growth.

• Scaled IT infrastructure to support rapid company growth: oversaw servers, virtualization, DNS/DHCP, backups, and user account management across Windows/Linux environments.
• Established site-to-site MikroTik VPN connectivity between offices and deployed Asterisk IP telephony, enabling seamless inter-office communication and reducing telecom costs by $10K/year.
• Deployed HP/Dell servers with CentOS, Debian, and Windows Server 2012/2019. Introduced 1C/PostgreSQL on Linux, cutting system downtime by 30%.
• Managed IT procurement, vendor negotiations, and license compliance for 130+ endpoints, improving operational efficiency and reducing delays in equipment provisioning.

Environment: Windows Server 2012 / 2019, Linux (CentOS, Debian), Active Directory (DNS/DHCP), MikroTik RouterOS, Asterisk IP telephony, PostgreSQL, 1C.