Dejaun Gayle

IT Professional | Systems Engineering, Security & Automation

About Me

A highly motivated Computer Science graduate (B.S., Cybersecurity Option, Distinction in Research) with extensive hands-on system administration experience across both Windows and Linux environments. I possess a proven ability to diagnose complex technical issues, implement robust network security measures (firewalls, access controls), and manage complex virtualized infrastructure (Proxmox/VMware).

I am driven by a passion for applying system engineering principles to design, build, and maintain efficient, automated, scalable, and secure solutions. I thrive on tackling diverse technical challenges, continuously learning new technologies from virtualization and containerization to security automation and cloud concepts, and leveraging my skills to solve real-world problems.

I am actively seeking challenging roles in System Engineering, Administration, Security, or DevOps where I can contribute to high-performing teams and make a tangible impact on infrastructure reliability and security.

Technical Skills

A broad range of technical skills acquired through academic coursework, work experience, and extensive hands-on project work in my home lab.

Operating Systems Linux (Debian, Ubuntu, Kali) Windows Server (2016-2022) Windows 10/11 MacOS
Scripting & Automation Python (Intermediate: Tool Dev, APIs, Parsing) PowerShell (Intermediate: AD, M365, Server Mgmt) Bash/Shell Scripting API Integration (REST)
Virtualization & Containers Proxmox VE (Cluster Mgmt, LXC) VMware Hyper-V Docker Docker Compose Portainer ZFS Storage
Directory Services & IAM Active Directory Group Policy (GPO) ADUC Okta (User Mgmt, MFA) LDAP Concepts Access Control Principles
Networking TCP/IP Suite DNS (Bind, Cloudflare) DHCP Firewalls (Sophos, UFW, Proxmox FW) VPN (Tailscale) VLANs / Network Segmentation SMB/CIFS Wireshark Nmap Cloudflare Tunnel Reverse Proxy (Caddy)
Security System Hardening (Linux/Windows) IDS/IPS Fail2Ban Threat Intelligence APIs (VT, AbuseIPDB) Zero Trust Principles Vulnerability Assessment Basics Email Security (SPF, DKIM) Log Analysis FERPA Compliance
Monitoring & Logging Grafana Prometheus Splunk (Basics) Node Exporter Rsyslog Centralized Logging
Tools & Other Git / GitHub PuTTY/SSH MySQL SharePoint BeyondTrust Remote Support Ellucian Banner Postfix/Dovecot M365 Admin Center
Soft Skills Problem Solving Communication (Technical & User-Facing) Team Collaboration Adaptability & Learning Agility Leadership & Mentoring Decision Making Critical Thinking Documentation Process Improvement

Work Experience

Junior System Administrator

Kean Information Technology
Sept 2023 – Present
  • Resolved complex escalations during Google Workspace to M365 migration (mailbox sync, duplicate accounts, mail delays, vendor accounts) using M365 Admin Center, ADUC, and PowerShell, documenting solutions.
  • Led and mentored 13 student technicians handling L2 M365 support (scheduling, training, escalations); improved efficiency by implementing a structured escalation process and coordinating with other IT teams to meet SLAs.
  • Deployed and managed print configurations for 156 campus-wide MFPs using Group Policy and AD security groups, successfully handling diverse driver requirements across multiple OS versions/models to improve security and simplify end-user setup.
  • Implemented a centralized Scan-to-Share solution for ~156 MFPs using SMB shares hosted on Windows Server 2022, managing permissions via AD security groups to replace USB scanning and boost user productivity.
  • Researched, compiled, and presented a technical proposal to the VP of IT/CIO for a PSI-approved testing center, detailing hardware requirements (workstations, networking, security cameras) and vendor/cost analysis; proposal advanced to funding review stage.
System Administration Group Policy Management Active Directory Print Server DHCP Management PowerShell M365 Admin Troubleshooting Leadership Process Improvement

Helpdesk Analyst

Kean Information Technology
Oct 2022 – Sept 2023
  • Resolved an average of over 11 technical support tickets per shift via phone, email, and remote sessions (BeyondTrust), addressing account access, hardware diagnostics (post-Win11 updates), and software support, maintaining a ~93% FCR.
  • Developed KB articles, step-by-step guides, and technician solutions using SharePoint; restructured support portal content/categories, contributing to a 20%+ reduction in common support requests.
  • Advised on knowledge transfer during transition to BlackBelt Help support services by analyzing user feedback/call volume data and providing targeted internal training materials/recommendations.
  • Processed user access requests (MFA resets, password changes, group updates) using Okta as primary tool, supplemented by ADUC and PuTTY, ensuring FERPA compliance.
Technical Support Troubleshooting Okta ADUC PuTTY SharePoint Knowledge Management Customer Service FERPA Compliance BeyondTrust

Projects

Hands-on projects demonstrating practical application of system administration, engineering, automation, and security skills.

Infrastructure & Virtualization (Home Lab)

Comprehensive self-hosted environment built on server-grade hardware for learning, testing, and running production services.

  • Designed, built, and manage a multi-node Proxmox VE cluster (ThinkServer RD550) utilizing ZFS (RAID1 for OS boot, RAID5 for VM/LXC storage) ensuring data redundancy and integrity.
  • Hosts diverse workloads including Linux LXC containers (Debian, Ubuntu) for lightweight services (Caddy, Cloudflared, AdGuard Home, Rsyslog) and full VMs (Windows Server, Linux distros) for testing and application hosting.
  • Configured Proxmox networking (bridges, VLAN tagging concepts) to segment traffic between different services and security zones.
Proxmox VE Linux (Debian) ZFS Virtualization LXC Containers Server Hardware Networking

Python Network & Security Tool Suite

Custom-built Python tools for automating security reconnaissance and threat intelligence gathering.

  • Engineered a modular tool suite using Python (`requests`, `json`, `re`, `dnspython`) to automate querying of external APIs (VirusTotal, AbuseIPDB) and perform DNS lookups for IP reputation analysis.
  • Developed components for network device fingerprinting (leveraging OSINT and potentially passive analysis concepts).
  • Implemented robust multi-key API management with rate limiting respecting free-tier constraints, exponential backoff for transient errors, and progress tracking for large datasets.
  • Included automated result parsing and generation of actionable recommendations (e.g., Block/Investigate/Monitor) based on aggregated threat data, significantly speeding up security investigations.
Python API Integration Automation Security Threat Intelligence Error Handling Data Parsing

Containerization & DevOps Practices

Deploying and managing applications efficiently using Docker and related tools.

  • Utilized Docker and Docker Compose to define, deploy, and manage various containerized applications (Caddy web server/reverse proxy, AdGuard Home DNS sinkhole, game servers like Minecraft) on Linux hosts within the Proxmox environment.
  • Managed container lifecycle, networking (macvlan, custom bridge networks), resource allocation (CPU/memory limits), and persistent data storage (volumes) using Portainer GUI and Docker Compose YAML files.
  • Streamlined application deployment, updates, and configuration management, improving service reliability and simplifying maintenance compared to traditional installations.
Docker Docker Compose Portainer Linux DevOps Concepts Container Networking Application Deployment

Infrastructure Monitoring Stack

Implementing real-time monitoring and visualization for home lab infrastructure.

  • Deployed and configured the Prometheus, Node Exporter, and Grafana stack (often via Docker) to collect and visualize real-time performance metrics from Proxmox hosts, VMs, and containers.
  • Collected metrics including CPU usage, memory utilization, disk I/O, network throughput, and system temperatures.
  • Created customized Grafana dashboards with graphs and alerts to provide actionable insights into system health, identify potential bottlenecks, and improve overall infrastructure observability.
Grafana Prometheus Node Exporter Monitoring Observability Docker Data Visualization

System Security Hardening

Applying security best practices across Linux and Windows systems.

  • Implemented robust security measures including fail-safe login configurations, custom port firewalls (UFW on Linux, Windows Firewall), and automatic IP banning for brute-force protection (Fail2ban).
  • Applied the principle of least privilege for user accounts, service permissions, and file system access on both Linux and Windows Server environments.
  • Secured remote access using VPN tunnels (Tailscale) and strong SSH key authentication practices (key rotation, disabling password auth).
  • Performed periodic vulnerability scanning using tools like Nmap to identify and remediate open ports or misconfigurations.
Security Hardening Linux Security Windows Security Firewalls (UFW) Fail2Ban Least Privilege VPN Nmap

Web & Email Systems Administration

Deploying and managing secure, self-hosted web and email services.

  • Managed personal domain (`futureforge.xyz`), utilizing Cloudflare for authoritative DNS, DDoS protection, and secure tunneling (Cloudflared) to expose self-hosted web applications (React builds, internal dashboards) without opening firewall ports.
  • Deployed, configured, and secured a complete self-hosted mail server stack on Linux using Postfix (SMTP relay/delivery) and Dovecot (IMAP/POP3 access).
  • Implemented email security best practices including DNS record configuration (MX, SPF, DKIM, DMARC) to improve deliverability and prevent spoofing.
Cloudflare DNS Linux Postfix Dovecot Email Protocols Web Hosting (Caddy) Security (SPF/DKIM)

Sophos Firewall & Zero-Trust Network

Implementing advanced network security using an edge firewall.

  • Architected and configured a Sophos firewall (virtual appliance) as the network edge gateway for the home lab environment.
  • Implemented network segmentation using VLANs and firewall rules to isolate different security zones (e.g., management, servers, user devices).
  • Configured advanced Intrusion Detection/Prevention System (IDS/IPS) policies and enabled traffic/application monitoring for enhanced network visibility and threat detection.
  • Applied zero-trust principles through granular firewall policies restricting inter-VLAN traffic and enforcing least privilege network access.
Sophos Firewall Firewall Rules Networking Network Security IDS/IPS Zero Trust VLANs

Research Experience & Publications

Research Programs

Google - CAHSI Collaboration
January 2025 – Present
Focus: Artificial Intelligence, Cybersecurity, and Social Impact initiatives
AI Research Cybersecurity Collaborative Research
Kean University Internship (SpF)
May 2024 – August 2024
Focus: Transformer Neural Networks and LLMs for airborne surveillance systems
Neural Networks Computer Vision Drone Systems
Computing Alliance of Hispanic-Serving Institutions (CAHSI)
February 2024 – July 2024
Focus: Multimodal adversarial testing of LLMs and image generators
Adversarial AI Security Testing LLM Research
Louis Stokes Alliance for Minority Participation (LSAMP)
October 2023 – December 2023
Focus: Security vulnerabilities and mitigation in Large Language Models
AI Security Data Analysis Technical Writing

Presentations & Publications

  • [1]
    D. Gayle and Y. Kumar, "Detection and Mitigation of Multimodal Adversarial Attacks," presented at the Annual GMiS Conference, Fort Worth, TX, Nov. 6–9, 2024.
  • [2]
    D. Gayle, B. Hannon, Y. Kumar, and J. J. Li, "Navigating Adversarial Prompts to Secure Large Language Models," presented at Kean Research Days, Union, NJ, Apr. 17, 2024.
  • [3]
    B. Hannon, Y. Kumar, D. Gayle, J. J. Li, and P. Morreale, "Robust Testing of AI Language Model Resiliency with Novel Adversarial Prompts," Electronics, vol. 13, no. 5, p. 842, 2024. View Article

Education & Affiliations

Kean University

Union, New Jersey

Bachelor of Science in Computer Science

Specialization: Cybersecurity

Expected Graduation: May 2025

Distinction in Research
Computer Science Cybersecurity Research Academic Excellence

Organizations & Memberships

  • Center for Cybersecurity

    March 2023 - Present

    Active member participating in cybersecurity research and training initiatives

  • Association for Computing Machinery (ACM)

    October 2022 - Present

    Member of premier computing society focused on advancing computing as a science and profession

Professional Development Networking Leadership

Get In Touch

Looking for Opportunities

I'm actively seeking opportunities beginning May 2025 in System Engineering, System Administration, DevOps, or Cybersecurity roles. I'm passionate about building secure, reliable, and automated systems. Let's connect!

Contact Me via Email