System Administrator
Dmitry Evgenyevich Gusev
18+ years experience · Linux · Zabbix · VMware · Cisco · MikroTik
100+
servers managed
500+
hosts monitored
30+
sites maintained
5 years
of backups without failure
About
Location: Moscow and Moscow Region
Work options: on-site or remote
Driving license: Category B (10+ years)
Passport: valid
18+ years in IT:
- CEO of IT integrator "IT Solutions" LLC
- CTO of IT integrator "SysAdminGroup" LLC
- System Administrator at data center
- Senior System Administrator at ISP
- System Administrator at ISP
- Technical Support Specialist
Public activities:
- Founder MPA ROBOCOP "Armed Citizen"
- Member of the Supreme Council MPA ROBOCOP "Armed Citizen"
- Head of Moscow branch MPA ROBOCOP "Armed Citizen"
Portfolio
1C:Medicine on Dedicated Server
- Challenge
- The clinic needed stable and secure 1C:Medicine operation with role-based access to patient personal data and zero risk of database loss.
- Solution
- Deployed 1C:Medicine on a dedicated server with PostgreSQL, configured role-based access model, automated backups with restore verification, and optimized queries for the workload.
- Result
- The system handles the clinic's daily workload reliably; patient data access is role-restricted (152-FZ compliance); regular backups with test restores eliminate data loss risk.
RDS Terminal Server for Accounting
- Challenge
- The property management company's accounting team needed secure remote access to 1C and work applications from any device — without installing software on personal computers.
- Solution
- Deployed Remote Desktop Services terminal server, access via VPN tunnel, user rights and environment via GPO; workstation environment centralized on the server.
- Result
- Staff work with 1C remotely from any device over a secure channel; data never leaves the server; updates and administration from a single point.
Active Directory Implementation and Migration
- Challenge
- Transition from scattered account and resource management to a centralized domain infrastructure on a live industrial site without production downtime.
- Solution
- Deployed Active Directory from scratch, configured DNS, DHCP and Group Policies, migrated users and resources.
- Result
- Single point of control for accounts, permissions and security policies; new employees are onboarded by template in minutes; migration completed with zero production downtime.
MikroTik Mesh Wi-Fi for Glamping
- Challenge
- Full Wi-Fi coverage across the glamping territory with seamless roaming between cabins and recreation zones, with guest device isolation.
- Solution
- Built Mesh network on MikroTik managed by CAPsMAN: 4 isolated SSIDs (management, service network, guest, IoT), seamless roaming, centralized AP management.
- Result
- Guests roam freely without connection drops; the entire network is managed from a single console; guest devices are isolated from each other.
Anti-spam and Email Security Hardening
- Challenge
- The company needed reliable protection of corporate email from spam and phishing without losing legitimate messages.
- Solution
- Deployed a mail stack on Exim + Dovecot + Rspamd + ClamAV, configured RBL filters, Bayesian classification, fail2ban and neural-network scoring.
- Result
- About 62% of spam is rejected at delivery time; legitimate mail passes without delay; attachments are scanned for malware.
Infrastructure Monitoring with Zabbix
- Challenge
- Dozens of servers and multi-vendor network devices needed unified monitoring with alerts raised before problems affect users.
- Solution
- Deployed and extended Zabbix (TimescaleDB, agent auto-registration), built custom templates for network hardware that had no ready-made vendor solution, and set up alerts to email, Telegram, Slack and Rocket.Chat.
- Result
- A single point of control for servers, network and applications; earlier fault detection; faster incident response.
Site Migration and Containerization
- Challenge
- Several sites on different stacks (Ghost, IPB forum, static) ran on one aging server with no isolation — a failure of one risked taking down all of them.
- Solution
- Containerized every site with Docker (nginx, Ghost, PHP), set up an nginx reverse proxy with DNS-01 SSL, and migrated everything to a new server with zero downtime, keeping the old infrastructure as a rollback path.
- Result
- Sites are isolated from each other, updates are safe, migration completed without data loss and with a fast rollback option.
How I Can Help
Infrastructure Audit
Inventory, bottleneck and risk identification, improvement plan
Monitoring (Zabbix)
Deployment from scratch: templates, SNMP, triggers, alerts, dashboards
Windows / Linux Servers
1C + MS SQL, RDS, file and web services, ongoing support
Active Directory
Implementation, migration, GPO, access rights management
Networks & Wi-Fi
MikroTik / Cisco / Juniper: BGP, VLAN, firewall, CAPsMAN, VPN
Virtualization
VMware / KVM: design, migration, server consolidation
Backup & Recovery
Backups with restore verification, data loss prevention
Managed IT Services
Regular IT infrastructure support and maintenance
Skills
Linux (Debian, Ubuntu, CentOS, FreeBSD)
administration: NGINX/Apache, mail, file services, Bash automation
Zabbix
infrastructure monitoring, custom templates (incl. SNMP), triggers, dashboards
Networks: MikroTik, Cisco, Juniper
BGP, VLAN segmentation, firewall, VPN (WireGuard / IPsec), mesh Wi-Fi network deployment (CAPsMAN)
Virtualization: VMware, KVM
design, migration, consolidation
Windows Server
AD / GPO, DNS / DHCP, RDS, 1C + MS SQL
NGINX / Apache
configuration, TLS, proxying, tuning
MySQL / MariaDB
installation, optimization, backups
Bash / Shell
maintenance and deployment scripts
Education
Moscow University for the Humanities and Economics (ANO VO MGEU) — Economist.
Hobbies
- Alpine skiing
- Role-playing games
- Hardware tinkering
- Firearms
- Military equipment
- Free software and automation
- IT education and outreach
Ready for New Projects!
Contact me to discuss collaboration