Mihai Costin Dumitrescu
33 Beaudry, Saint-Constant,QC
Summary
IT professional with over five years of hands-on experience in infrastructure support, now focused on system administration. Proven ability to deploy and maintain Windows Server environments (AD, DNS, DHCP, WSUS, WDS, GPO), as well as Linux VMs, automate routine tasks with PowerShell and Bash, and design, build, and manage virtualization hosts (Proxmox/Hyper-V). Strong troubleshooting mindset, resolving 200+ tickets per month with 98% SLA adherence, combined with solid backup/restore, monitoring, and user management chops. Bilingual (EN/FR), committed to maximizing server uptime, orchestrating seamless patch management, and driving continuous improvements through proactive monitoring and automation.
Overview
6
6
years of professional experience
Work History
IT Security And Endpoint Manager
Playground
Kahnawake, QC
01.2023 - Current
- Managed user accounts, group policies, and permissions for 400+ endpoints in Active Directory, reducing onboarding time by 40%.
- Developed PowerShell modules for user onboarding/offboarding and scheduled health-check reports—cutting manual provisioning time by 50%
- Deployed and maintained two Windows Server 2022 domain controllers (AD DS, DNS, DHCP) with automated WSUS patch pipelines, achieving 99% compliance.
- Hardened Group Policy Objects (CIS benchmarks) across 400+ endpoints, slashing vulnerability findings by 60%.
- Built and managed a Proxmox VE virtualization host for lab/DR purposes, provisioning and snapshotting 20+ critical VMs.
- Configured fault-tolerant DHCP scopes and DNS zones, including forward/reverse lookups, reducing address‐conflict incidents by 80%.
- Deployed Bitdefender GravityZone across 400+ devices, slashing malware incidents by 70%.
- Improved endpoint compliance from ~78% to 94%+ in under 6 months through automation, patch policy enforcement, and routine audits.
- Maintained inventory of hardware assets including servers, laptops, desktops.
Full Stack Software Developer
Flighthub
Montreal, QC
01.2022 - 01.2023
- Built and maintained customer-facing dashboards in React/Redux, enhancing incident visibility and reducing triage time by 25%.
- Integrated Slack and email alerts for system outages, improving team response time by 50%.
- Automated data reconciliation tasks with PHP/Laravel services, cutting manual processing time by 80%.
- Met with stakeholders, product teams and customers throughout system development lifecycle.
IT Specialist & Software Developer
Kinoklik
Montreal, QC
02.2021 - 01.2022
- Architected, developed and maintained Kinoklik’s web platform using React.js for the front-end and Python back-end services.
- Automated routine operations and system-administration tasks via Python and PowerShell scripts, reducing manual effort by 40%.
- Integrated third-party APIs (payment gateways, SMS/email services) and built internal RESTful services to expand platform functionality.
- Maintained and optimized SQL/NoSQL databases (PostgreSQL, MongoDB) schema design, indexing strategies, data migrations and routine health checks.
- Provided L2 technical support for internal teams diagnosing network connectivity, VPN and workstation issues, and training staff on new tools.
- Authored and updated technical documentation, runbooks and wiki pages to streamline onboarding and knowledge-sharing across the IT department.
IT Support Specialist
Air Canada Vacations
Montreal, Que
01.2019 - 02.2021
- Assist with the setup and maintenance of office peripherals (printers, scanners, headsets) for call-center staff, ensuring all equipment stays operational.
- Configured and troubleshot DHCP scopes (including failover), DNS zones and VPN connectivity (SSL/IPSec) to ensure 24×7 remote support.
- Led imaging projects using MDT and WDS: boot/capture, OS deployment and post-install configuration of applications and security policies.
- Authored infrastructure runbooks and knowledge-base articles, slashing repeat incidents by 20% and enabling rapid escalation handoffs.
- Monitor and maintain network connectivity, including VPN provisioning and troubleshooting for remote employees.
Education
Bachelor of Science - Cybersecurity
École Polytechnique De Montréal
12.2024
Certificate - Analyse Et Cybersécurité Opérationnelle
École Polytechnique De Montréal
2023
Certificate - Cyberfraude
École Polytechnique De Montréal
12.2021
Full Stack Developer Certificate - Software Development
Le Wagon
12.2019
Skills
Windows Server Administration
- Active Directory & Group Policy (AD DS, Sites & Services, FSMO)
- DNS & DHCP design, forward/reverse zones, fault-tolerant scope setups
- Patch management (WSUS upstream/downstream, GPO-forced updates)
- WDS imaging (boot/capture, unicast/multicast, sysprep)
Virtualization & Networking
- Proxmox VE / Hyper-V (host config, storage, snapshots)
- VLANs, vSwitches, basic Cisco/Ubiquiti switch setup
- VPN (IPSec/SSL) and firewall ACLs for remote access
Linux Server Administration
- Ubuntu/CentOS installation & hardening (SSH, UFW/iptables)
- Shell scripting (cron jobs, rsync backups)
- LAMP stack deployment and package management (apt, yum)
Automation & Scripting
- PowerShell modules for user onboarding, patch reporting
- Bash scripts for log rotation, backup automation
- Task Scheduler & cron for scheduled maintenance
Monitoring, Backup & DR
- Nagios/Zabbix or Splunk Free for log aggregation and alerts
- Veeam Community / Windows Server Backup for scheduled restores
- Runbooks & playbook creation for disaster recovery
Identity & Access Management
- Azure AD basics & hybrid join
- MFA rollouts, service accounts governance
- RBAC design and group nesting
Languages
English
Native/ Bilingual
French
Native/ Bilingual
Romanian
Native/ Bilingual
Work Availability
monday
tuesday
wednesday
thursday
friday
saturday
sunday
morning
afternoon
evening
swipe to browse
Software
NinjaRMM
Bitdefender GravityZone
Miradore
Intune
Active Directory
Timeline
IT Security And Endpoint Manager
Playground
01.2023 - Current
Full Stack Software Developer
Flighthub
01.2022 - 01.2023
IT Specialist & Software Developer
Kinoklik
02.2021 - 01.2022
IT Support Specialist
Air Canada Vacations
01.2019 - 02.2021
Bachelor of Science - Cybersecurity
École Polytechnique De Montréal
Certificate - Analyse Et Cybersécurité Opérationnelle
École Polytechnique De Montréal
Certificate - Cyberfraude
École Polytechnique De Montréal
Full Stack Developer Certificate - Software Development
Le Wagon
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